Thank you, I'm so happy that you liked my characters :D
I'm using both box and circle colliders. The top of the characters have a box collider so you can easier stand on them but the bottom part is a circle. I'm aware that the controls are a bit clunky and sometimes very unresponsive (especially when you're standing on top of a character). I might go back to the game in the future and do something more with it since I kinda like the idea I came up with.