Stability: While there were no crashes, there are some pretty amateurish bugs that might really be better described as poorly-conceived gameplay. Like enemies moving to a point where you can neither kill them, nor shoot at them to get past them. Or bullets doing no damage unless the enemy sees you, even if it looks like you should be able to hit them. .
Content: Some mildly interesting monster designs, but otherwise nothing worth noting. The level designs are quite uninspired. The game is very monotonous and the difficulty comes mostly from poor design and bad mechanics. That's what pads out the playtime- frustration and tedium. No puzzles or stealth mechanics. Just two guns, limited ammo, and lots of grindy garbage.
Gameplay: Incredibly tedious and frustrating, doubly so because the enemies soak up bullets, which are finite and run out easily. There's no way around most of them except to kill them, however. You basically have to save regularly and repeat the same, very samey areas over and over again and hope you don't screw yourself over ammo-wise and have to start the game all over again. Basically impossible without using cheat engine. There is no fun to be had here at all.
Aesthetics: One word: bland. And that's being generous. The only thing even slightly decent is the background music, and even that gets old fast.
XXX: Ten pixel animations, all pretty decent, if simple- but ruined by overzealous censorship that, as far as I can tell, can't be removed. None of it is in gameplay, either- you basically have a separate gallery that unlocks after beating the game. Without the gallery, this would be completely devoid of anything remotely resembling an h-game, seeing as how you don't see anything even slightly risque outside that gallery.
Overall: I don't say this often, in regards to pixel platformer h-games, as even the worst usually have *something* worthwhile, but trust me- this is a total waste of time and harddrive space. Do yourself a favor and pass on this like I should have. The notion that they'd ask for money for this garbage is frankly insulting.