Thank you for the feedback!
I aggree with you on the fact that my game needs to introduce its mechanics more gradually, one by one. Especially, if it become a serious game!
I'm happy to hear that my concept has potential for a serious game, that's great!
Concerning the theme, the goal was to get only one set of caracteristics and not one monster. The theme is maybe not at the center of the gameplay.
Anyway, thank you again!