First off I just want to say the presentation is fantastic! I especially love the intro cutscene and your cover art. One thing I think could dramatically improve the game is just to modify some of the platform positions such that players are less prone to getting stuck/glitched out on platforms. (Ex of this might be the purple and blue platforms on level one being too close to each other). Understandably this might be difficult with a fixed jump height but you could assign separate jump heights for each twin. :)
Please take a chance to review my game if you have the time.