I enjoyed this a lot! The upgrades feel really nice, it has good roguelike energy.
Unfortunately I wasn't able to beat it after a little over 10 tries, so the difficulty may be something of note. Also, the collision damage (with the walls and obstacles) felt a little unfair, even randomly triggering sometimes. I like the idea of smacking into walls and taking damage after a big hit, but the way that it was implemented led to a lot of moments that didn't feel fair.
Nice job overall!
Viewing post in Super Serious Turtle Battle jam comments
Holy goated I loved your game, but yeah our physics system definitely leaves something to be desired haha. Certain walls didn't seem to absorb impact the same way others did so it leads to situations where the turtle is just speeding up by hitting walls a bunch of times and starts taking massive damage. As far as difficulty goes I think it comes mostly from the lack of balance in upgrades. The cannon and sword are just awful pick ups, but balancing is something we just got to a little too late. Glad you enjoyed the game though, thanks for the feedback!