Played on Linux, finished all levels and found all the eggs, no issues except for touching the blue thing that says lv_snow.CS_.1 on top of the mountain level will take away controls until you quit the level.
Nice concept, this sort of cooperative platforming is always fun to see though I haven't played many of them. Lost Vikings comes to mind. Now the game really needs more complex levels with more cooperation between the characters instead of just separate paths they have to take. It was already getting there with the last levels of the main storyline, I especially liked the spider throwing mechanic near the end.