The gameplay are nice, i really the movement control of the player. The boss are pretty chanllenging but it isn't unfair, which is nice. And the visual and music are nice too. Basically the overall quality of the game are great.
There is a room that if you enter the game crash, which is fine since it is game jam but the room under it can go up to that room through the secret upgrade place and i dont think it suppose to be able to do that. Also not sure how to go through the 2 hits kill river, maybe its same as area 3 which is unfinished?
Anyways, really ncie game!