OK, unlike the other reviewers so far I actually finished and I think the game is ALMOST BRILLIANT but the flaws holding it back are so annoying! Looks and sounds aboslutely beautiful but very frustrating to play as others have said - in a game which is so punishing on precision, shouldn't the hitzones be more accurately defined? It's hard at first to tell when the laser beam will kill you, similarly why are the tentacles lethal when they're emerging from their burrow but harmless while going back in? The gameplay has a lot of difficult timing of jumps/combos that you have to master because of how far apart the checkpoints are, but I kinda like the sense of achievement when you do figure out a way to consistently finish a section. The bad side is that you often have to make leaps into the unknown and get killed by something you couldn't have possibly seen.
The tutorial aren't very helpful, I don't think it ever explains that you can climb up/down the green beams with A/S or - though you figure this out early, hopefully, that S lets you fall through a platform. I guess that's all intuitive because it's so standard, but wall jump works a bit weird in this game and I didn't find the tutorial explained how it worked clearly. It sounded like you use A/D to cling to a wall then jump away in the opposite direction. But while you CAN do that, the most important skill is to stay stuck to one wall by holding that direction key while quickly pressing the opposite direction key so you can just "slide" vertically up the wall.
I had to give up after acquiring the dash function (as someone else said, this would feel smoother and more fulfilling if you had collected them somehow rather than suddenly being granted them by the guy you communicate with) because CONTROL IS A TERRIBLE KEY ON A WEB GAME. You start getting browser options pop up as soon as you start using it in combination with other keys - I don't know how many times I saved the game as a bookmark. Then finally had the w key pressed (hands in the AWSD position) and CTRL+W closed the browser window. Annoying.
Should really let players redefine keys for situations like this! Also left click for shoot was probably unnecessary, could it have been something that didn't require the mouse? Almost anywhere on the keyboard near AWSD would have done. Oddly the arrow keys work and for some purposes they're more useful than AWSD but bizarrely they work differently to AWSD - functions on up/down don't match W/S, and the wall-jumping is apparently non-functional using left/right unlike A/D.
Also to go through the options menu eg to change the audio or fullscreen means you have to restart the game? That's just silly. Oh and the boss appearance was kinda silly too, could it have been something more...alien?
But there were also lots of good points. There was a real sense of "place" in the different sections, particularly when you go deep inside the planet in the antigravity section. There was a plot that kinda made sense and was reflected in the gameplay. The script was written in excellent English which is good as sometimes poor spelling/translation lets the plot realism down. There was a huge sense of achievement from finishing it and you do wonder "what next". If players enjoy challenging platformers where rhythm is important and far apart checkpoints force you to master short sections of gameplay before you can progress, Star Dust is worth a try. https://www.newgrounds.com/portal/view/757012 Very different, but creative, vibe to that game, and the controls are less convoluted.