Later on when you can swim and pass the cave where you need to use thew boulders to progress in it, the next town has a prison you need to go to, touching the statues changes the locked door positions around the map. The final boss himself needs to be brought to 0 HP once, then weaken him while using one of the two pentagon scroll looking items, the yellow one first, and then the red one. Note that it's RNG based when they actually work on him, so you'll have to be spamming them pretty often. Be prepared to heal a lot.
There's 3 endings in the game based on your lust points and possibly the amount of H events unlocked. 1 - 20 = lover ending. 21 - 80 = NTR (Undiscovered) ending. 81 - 100 = NTR (discovered) ending. There are two items in the game that can increase and decrease your lust points in the game by 3 points.
Personally, I don't think the NTR was fleshed out very well in this H game. The couple didn't have that much time together, you're already in love and have one night of passion before it all begins. She becomes a slut mostly thanks to the final boss' lust curse and gradual corruption. I'd say this H game is better as a corruption theme based H game with NTR on the side to contribute to that. But man, there was a ton of content at least to make up for all the grind.
