Thanks for playing!
If you do decide to try again, the game autosaves after every level, so you wouldn't have to do all previous levels again. Also, if you die a few times, the time you get for that planet secretly gets a little longer, so even if you don't find the perfect solution, you'll get there eventually! Oh and there's also a full playthrough video on youtube linked in the description of the game page, if you can't be bothered but want to see the ending anyway :P