The fact that if one player enter the door he will stay untill the other one reach the door was something I didn't thought about in the first place, but It turned out that on some levels it was imposible to make it both at the same time. Also it means more difficulty, which some people will find it too hard.
Definitely is something to keep in mind and maybe in the future I could add a hard mode or something that force you to end with both characters at the same time.
Thank you very much! <3