I loved the game! I've already passed it by taking the most damage from enemies, as well as passing it with zero damage.
Not a suggestion, but I would like to see more enemies with the tentacle, fly and spider mechanics! Losing to them increases the difficulty because they create more enemies. ;D
(Edit)
If possible, it would be great to be able to see the size of Syahata's belly in real time (eggs, or other creatures that may leave something inside it) and not have to open the menu.