Thanks for checking the game out & for the feedback! My playtesters did have the most trouble with level 6, so I'm attaching a solution video, in case you want to check out the rest of the game.
I was planning on making the blue character square to better differentiate them, but ran out of time. I think triangles pointing different direction would also work. I have an idea for making level 6 a lot more manageable with just 2 new tiles, so I'll make that change once the jam is over.