This is a very interesting game, your character starts off barely able to defeat a single mob but you will quickly be able to upgrade your stats, entering an arms race with increasingly tougher enemies who are always just one upgrade away from being overmatched by your weapons. Then there are energy upgrades (which regulates shooting, evasion and special attack actions), locked rooms containing special powerups and armor upgrades, all which compete with the firepower upgrade and leads to interesting choices on which upgrades to prioritize.
The amount of upgrades you use is also tied the ending rank and leads to entirely different playthroughs. The enemies that give you experience do not respawn so you have to strategize how to minmax your characters stats with limited amount of upgrades and beat the game for the first ending. However, you can respawn enemies to farm experience points by breeding and giving birth to them; this is an absolutely genius implementation of pregnancy and sex mechanics into a H-game and more games need to do this! By doing this, you can farm infinite upgrades to fully upgrade your character but this affects your ending rank. The armor upgrade in particular will completely change the game...
The erotic content is perfect, the heroine is blonde haired with pink highlights giving her a cute punk girl tomboy look. Every kind of interspecies alien you can think of is covered here and there is plenty of impregnation. For this price, the erotic illustrations alone are well worth it but it is also integrated extremely well into a game as whole and makes the package all the more satisfying. Definitely recommend.