I wasn't quite sure what to do once I fell off the tall blue platform into the box with the 4 coloured circles, aside from holding down the left mouse button and  WASD in hopes of making something happen, desppite there being no indication that I'm successfully moving in a chosen direction :(

Do have a look at the game and try it out again to find out what the problem is, then put up an explanation in either the level itself or the game's main page. Cheerio!