The plot was good (who wouldn't want to escape a mental hospital?) and the idea for having three different people working together was nice, especially with each of them having a certain attribute (strong, little, and slingshot).
1) If you're going to go to all the trouble of color-coding the keys, color-code the locks too. It's a bit frustrating to have a key, see a keyhole, and not have any explanation as to why the two don't go together.
2) Things like pieces of paper (which can be read by anyone) and bottles of horribly corrosive acid (which can be dumped by anyone) shouldn't need a specific person to be read or dumped. I got the slip of paper with the little guy and couldn't figure out what to do with it because only the medium one could read it.