Was there an actual ending? I got to a scene that says space to skip, but nothing happens, then the portal boots me back. The atmosphere of each dimension was pretty cool, but the whole 'look for hints to know the correct portal' was initially confusing and towards the end uninteresting. I started off assuming that the color they said was wrong, because look at them, they're dead. Why should I listen to them? I eventually figured that out, but afterwards the mechanic didn't really add anything. The hints literally spell out the color in full caps, and is in an easily accessible spot each time. Perhaps if hints were a tad more cryptic, or if multiple hints needed to be used together? Even then, being knocked back on the first try was kinda annoying, cos I ended up playing the first level three times. The second level was brutally difficult, and left me wishing that the jetpack would charge faster.
Otherwise the game was pretty awesome, great atmosphere and lovely pixel art. The dead hint-bearers everywhere certainly added to that mood, and so did the amazingly composed music. I was interested to know what was going on, but apparently I won't get to find out. One final closing tip I have is to consider avoiding colour to represent stuff. I'm not colorblind, but many people are, and I'd imagine this would be impossible for most colorblind people.