As previously discussed, the dlsite trial, and the ci-en free verson both contain content up to 2-1, providing 1 new boss, 2 new enemies, and a bunch of animations (new animations for 1-2 boss, 1-4 boss, 2-1 soldier, 2-1 trap, home base plant)
The 500 yen support option gives you access to 2-2, which in addition to the above adds an extra enemy with its own animations.
Pollution stat has a significant effect on lust gain rate in grabs now, loading up my save with ~70 pollution made it impossible to get hypnotised, Hasumi ends up cumming before the grab gets that far. Pollution is lowered by 5 each time you use the houseplant.
I've found three new status so far, two levels from the milking trap, the first appears non-functional/just makes hasumi lactate on orgasm? the second applies a constant drain effect on her transformed state, presumably she's leaking power through her milk. Edit: also seems to increase pleasure gain from nipple stimulation, any grabs involving her breasts make hasumi cum very fast with this.
The third is restricted to the paid version, aphrodisiac status from the 2-2 enemy, causes lust gain while in their cloud and collision/attacking the trees caused a grab.
Currently messing around with status effects and enemies to see if there's anything extra.
Edit: found something cool, you get a bad end if you try to face the world 1 final boss while you have a stage 2 demon seed parasite inside you. Ends in a nice animated GO screen with hasumi giving birth.
Edit 2: Ok, the houseplant is seriously cool. In addition the the scene you get the first time and the animation you can freely go through after, if you feed it enough it'll evolve to a bigger plant, with its own scene and animations, that absorbs pollution even faster. You can even hit it to make it refund you the pollution it absorbed, and doing it enough will cause it to de-evolve back to base state. Gonna grind some more pollution to see if there's a third stage. Highly recommend getting machine translation if mind control/hypnosis/aphrodisiacs are your thing, cause the scene are pretty hot, theres a sense of "this thing is growing beyond my control", both in the sense it's getting bigger&stronger, and Hasumi is succumbing to the pleasure.