Now I start in a room that has one exit, but I can't pass due to an invisible barrier. Jump only works when the white thing is underneath my feet, but it doesn't stay there, so I gotta hit Space in the right moment, while standing at the exit of room 1.
So that was a little riddle at the beginning.
Controls are nice, but I still cannot jump far enough for the first bridge gap. Maybe the jumping doesn't use delta-T ? IDK about unity, some of it already does delta-t, so if you add it in your script, there could even be two delta-t routines, and the two delta-t factors mess things up like a double-negative.
Delta-t: (more of a public notice) For instance, take a theoretical 30 Hz framerate, calculate 33.3 / by the milliseconds one frame actually takes in your game, this gives factor delta-t, that can be used as a multiplication factor for all motion, so one would always jump the same height, regardless of a users framerate.