Going to write a somewhat not-so-thorough guide for anyone struggling with progressing, there's a bit towards the end that I'm not entirely sure of since I just let my character lose to the final boss for fun. that I'll probably edit in once I've gone back, but for now yeah.. incomplete guide.
Some basic things first: Your character is much stronger than the mobs, most except bosses are usually one-shottable unless you're affected by one of the many h-status ailments. Because you're so strong they basically only resort to h-attacks to subdue the protaganist, so your goal is to avoid as many h-attacks as possible, especially the ones that restrain your character, and stopping and going back to base to replenish and remove some of the harder to remove ailments is a good idea. To remove the more common status ailments in the menu under skills there's a skill that costs 83mp, 20tp that will get rid of some of them, another one that costs 3tp that will wipe off sticky stuff. Losing to a boss will permanently net you some status ailments that as far as I know can't be removed, but if they can it'll be at the NPC back at home base in the kitchen by the sink. The strategy to making it to the end is not to lose to any of the bosses, (or any of the regular mobs), so save before the boss and if your goal is to beat the game try and avoid losing whenever possible.
Some strategies with combat to help you with the bosses: don't let yourself get caught if possible, if your character has cummed there's a good chance you'll be restrained anyways, but most of the time you have the option to try and avoid being restrained, the option that costs 100mp and the one that costs 60tp pretty much have a 100% success rate, so use one of those, and try and keep your TP above 60 using the bottom right skill that costs nothing if you need to. A lot of the times especially if the boss isn't buffed up you can just focus on attacking and then spend 100mp every time they try and restrain you, but keep a few magic potions on hand just in case. 魔力剤 is the name of the potion that will replenish magic. If you find you're not doing as much damage as you need to you're probably inflicted with a status ailment that lowers your damage, or crit rate, so use some of the steps i mentioned above to cure them, definitely helps to do these in-between battle. Another tip, if you're running low on mp from removing h-statuses all the time, if you find yourself facing one of the weaker mobs that doesn't do anything too special you can use that one move that raises your TP and costs nothing, then use another skill that converts TP into MP and keep doing this until your mp is full.
1st stage: Forest
Goal is to defeat a giant squid boss, at some point you'll find an area filled with pink asphoradic gas, at which point you'll get a cut-scene and meet a succubus. You have two options after this, proceed through the gas-filled forest anyways, fight a buffed up but beatable boss because of the effects of the gas on you, or go back to last area, and continue on through the forest to the southeast, where you'll find a straight passage surrounded by a pink asphoradic liquid on either side, in each of the four corners of this area you'll find a plant , you'll need to collect the substance from each plant, and it'll help you cure the gas that leads up to the boss area and will make easier to beat. Oh, and you'll get ambushed by mobs every time you take something from one of the plants. I don't think the tree at the end of the path has any importance, but someone can correct me, there's goodies at the end anyways. At this point you should be facing the boss and will be able to proceed to the next area.
2nd stage: Abandoned Village
Goal here is to rescue a girl from some sort of magician boss on the stage. You'll get a cut-scene upon entering, and sent back and will need to go off to the right. In the next area you'll find a room with that succubus you met in the forest messing with a computer this time. She'll send you to some kind of mirror world, and interacting with the mirrors will bring you back and forth between the two worlds. You'll get ambushed before being able to actually progress or anything, so beat those enemies first. There was a wall of garbage that was blocking your path before, but if you're in the mirror world, that garbage path should be clear, and you can move north towards the boss area. There'll be a mirror right in front of next area that leads to the boss, you'll be able to exit the mirror world from there and still proceed to the boss, so you probably should do that, though I haven't tested what happens if you don't. Save and fight the boss, make sure you're not getting restrained by spending 100MP/60TP, try and use your 3 striking 13tp attack, this will gun down any enemy fairly quickly, and what I use for most bosses, there might be a skill you can by at the base that's better and uses MP, but this has gotten me to the end of the game so feel free to use only this if you can't find anything better. As long as you aren't getting restrained, and using that triple attack that boss should be easy and you should already be able to move on to the next area. That entire thing is really short, so if you want to explore around in the next area instead of fighting the boss feel free to, there also might be a way of making him weaker, but you shouldn't need it.
3rd stage: Research Lab
This one will take a considerable time, there's lots of navigating through ventilation shafts, and disabling and enabling computers, so if this one gets frustrating, sorry I'm too lazy to be specific in every area to be able to safely navigate you through each individual area, sorry in advance. past the main entrance area you'll find yourself in a room with a big computer and a woman. Surprise surprise it's the same succubus again, she'll activate the computer and then bait you into walking into a trap, which you'll see is just a metal line on the floor that glows pink when you cross it. In general you want to avoid triggering these if at all possible (obviously you can't in this one since it's a cut-scene) by deactivating a smaller terminal that's generally located somewhere near the trap itself. I haven't paid too much attention to whether or not some areas have small computer terminals that deactivate a trap far away, but the general strategy seems to be, see a terminal you've never seen before? click it, and save before you walk over the traps if you aren't feeling brave. At some point you'll defeat a group of enemies that will drop a 4 digit code that you'll be able to find later in your inventory, this code will help you unlock the nipple vibrators if you every get them put on you by any of the men in the area. They don't seem to be too powerful if you let them get put on, but they will stay on you unless you find one of the bigger computers located throughout the area where you'll be able to enter that 4 digit code you got earlier.
This place is rather large, and my memory is foggy so you'll have to struggle your way through this one, going through the ventilation shafts to progress further and further into the lab. Eventually you'll run into a mob that will start running towards one of the terminals to turn it on so that you're forced to walk through the floor trap to progress, but you can run towards them, catch up and take them down before they have the chance to activate it. It definitely helps to save frequently in case you mess up or because of my shitty directions, just know that I think the current version is bugged and you can't (or at least I couldn't) transfer any save files anywhere, so the 20 save slots is all you have, try not to overwrite any important saves. There's going to be two paths you can take in this area, one through the doors, another through another ventilation shaft. Go through the doors first. At this point you'll reach a door that you can choose to bust into, or find another way around. you'll probably want to go around, forcing your way through results in a pretty long H-filled fight that you might want to experience at one point, but for now, if progressing to the final area is your goal, focusing on the boss is more important.
To the sides of this door there's two alternate routes, one of which have a large computer that has the option to turn off one of the bosses's abilities, you'll definitely want to do this if you don't want to slowly struggle through maybe beating the boss. The boss has 3 abilities that can be disabled to make the fight easier, so far I've only found the two, the third is probably in the room that you have to force your way into, and may or may not be worth your time to try and beat in order to get to the boss, if you want to do this area in one clean run without having to go back i recommend not, but you have options here. Starting with the left area to the doors you are given the option to bust down or to leave alone, there'll be a big computer, click on it, make sure you click off, and bam, one of the bosses' abilities is gone, though you can always leave it alone or turn it on later to make the boss harder. There's also a smaller terminal to the right of the computer in a separate room, this summons a mob and results in a funny dialogue you probably can't read since you probably don't know japanese. There's a possibility I'm just lazy/also can't read japanese, so feel free to press this since nothing bad happens.
Now the right area... I'm not sure if it's because I didn't have a save that was before I entered the room or because the computer in that area does nothing, but there'll be a trapped floor again, it may or may not be disabled for you, and I'm fairly certain you can just skip this room and avoid it entirely Go back through to the previous area, then head back even further to the area where they tried to trap you (or succeeded), and go up the ventilation shaft in this area. Make your way to the top left, save before you go down the shaft, as there'll be another magnetic floor trap. You'll need to disable it before being able to go back up the shaft, so make your way to the bottom left corner first, you'll need to activate two large computers to turn off the floor trap, then to the top right and it should be disabled. For whatever reason it's the smaller terminal this time that will disable the bosses's ability, so make sure to turn this one off. Now head back up the ventilation shaft again, and this go around back towards the start of the vent shaft, and work your way north. This time you should reach the boss area as marked by the big blue crystal that asks if you want to save. there's also a terminal that will tell you which of the boss' abilities are turned off, hopefully if my instruction weren't shit or you weren't you should have 2/3 of the abilities turned off. This should be enough. As will all the previous bosses, avoid getting restrained, use your triple attack, and prioritize any of the little robot bats first since they also can restrain you.
4th Stage: Succubus' Castle (these are all very rough lazy translations, don't blame me if the area doesn't look like a castle)
At this point you do have the option of just losing to the boss to get an alternate bad end where you can access all of H content and spawn enemies/bosses, so if that was your goal in the first place, you only really have to read up until the point where you reach the boss. And again I haven't fully finished this area so I'm going to be vague at points, feel free to hunt me down in rage later. There's lots of shit that likes to chase you around, so try not to get attacked from behind where they'll have advantage. There'll be girls throughout the dungeon that you can save, usually you'll have to fight off some enemies before rescuing them. Currently unsure whether or not saving them all does anything. To the left there'll be vines leading down, and another path to the right leading down. The vines down lead to a big area filled with lots of pink pools of asphoradics again (fun!), there should be 5 separate areas, 4 of which lead to flowers similar to the 1st forest area where you had to disable the gas using them. As for what they do this time, I have no clue, maybe I missed one, and maybe it disables a boss ability without telling you, assume it does something and find the 4 flowers anyways. the 5th area to the center right has a plant that you can't do anything with to my knowledge, maybe because I missed a flower. Go back up the vines or all the way to the south where there's a portal that brings you to the entrance area, and make your way back to the stair case next to the vines.
This next area has lots of little caves filled with trapped girls, feel free to save them, and yes slam your keyboard at how vague and unspecific I'm being throughout this section. There's two routes you can take, one with a starircase, another that isn't. The staircase route is all the way to the south, and then to the right, the non-staircase route is somewhere in the middle then to the right. The staircase leads to the boss, the middle area leads to an arena where you can save a girl. You've now reached the point where I went straight to the boss, and lost on purpose for obvious reasons. Again at some point I'll finish the walkthrough for now you get my best guesses and what other people have said in the thread. The middle route and saving the girl in the arena is probably where you want to go in order to weaken the boss and actually win, you're on your own, the next portion just tells you how to get to the boss.
Make your way up the staircase at the end of this area, there'll be 2 blue portals off to the left, it's a one-way exit at the end of the zone, so don't worry about it, you can't use it right now. Make your way to the right where you'll see a monster sitting up on a rock as a sentry following where you go, it'll hop down and chase you if you get too close, kill it or run past it. At this point you're going to have to pay attention/save and mess up/kill them anyways, any time there's a monster on the edge of a cliff looking at you they'll hop over and surprise attack you, so your options are let them surprise attack you, or go around and fight them directly. this happens at least 2 or 3 times in this zone, so it'll be a bit of a struggle, save often. At some point you'll start running into portals that'll let you hop in-between cliffs, make sure you don't take the one that returns you to the starting point since it's a one-way. At the end you'll find a big orange crystal, use it you'll teleport a bit before the boss area, yay you've made it. Save etc. and make your way to the boss. Again sorry for this being unfinished, come back in a few days.
