Nice! I agreed with bulboka's comment and I want to add that if you only play w/ 2 characters, maybe you could move one with WASD and the other with arrow keys, that will make the game more fluid.

Nice concept! Except to see interesting weaknesses of the fused form in post jam version.

Some issues:

White character has an invisible obstacle in his starting room.

Visually showing current active character would be nice. Also could use one button to switch back and forth between characters.

It's possible to go back from the room you've just entered. Then you find yourself in a glitchy looking brown place and can do nothing.

The basics are done, now it's time to make some interesting puzzles. Keep on working!