Neat little concept! reminds me of a gba version double dragon. few things. I wish i had the option to turn on and off music so i didn't have to mute audio.
Its hard to tell but I think I see 5 colors. You have your 4 primary colors of the game, but when you teleport its black and not dark purple....so that might have been a slight oversight.
I'm not sure if it was me or if others had this issue, but I had no way to scale the game up from the 160x144 resolution. and even with chrome at 6000% it was still a bit difficult to see what was happening. Not sure if it was on my end tho. If in your future jams you could ad a 1x or 4x mode so the person who is playing can see it at original gba size + scaled up to play.
overall very fun little concept that you could build out!