nothing so far
Don't you say? (!)
It's even possible to make mods of this? o_0 How?
Well you can edit the graphics and music in the data directory for starters. Functionality can't be changed currently, but who knows... I might allow that with RUMBLE.
I edited some graphics and sprites and stuff (so instead of having a sword, a ninja star) and besides changing the looks it kinda also changes the hitboxes so it changes the game a lot if you're used to it.
I changed the scrolling text to read nothing but "CHEESE" over and over again.
I'm a succesful human!