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!