Simple but fun game that has the theme of 2 dimensions in there for sure.
There could be some interesting levels made with this where you can only reach certain coins with one of the characters, or where the characters would need to work together by blocking eachother or walking against the platforms (so you would tehcnically only be moving one player then).
As it is, it's very limited but the potential is there.
Congrats on submitting to the jam!