Firstly- I just found out about strudel.cc, and it's pretty cool! Now, onto your game!
Gameplay wise the game consists of two parts. One is pure fun, the other is... well, less fun. Walking around the planet is not that engaging. There is no challenge to collecting crafting materials, so you mostly circle the planet, build a structure, then repeat it twice more. At that point you have enough stuff for building the rocket. This is where the fun begins. Building the rocket is cool. Flying it even cooler! Obviously I crashed the first one (cool touch with it falling into pieces), but with the updated design, and smarter navigation I landed just ok on my second try. Very cool experience!
Audio does it's part. Sound effects are sparse, but communicate everything pretty well. Music works for the atmosphere.
Graphics work, but could be better. I mean, at any point I could easily distinguish between the gameplay elements, but when you are on the planet they seem to lack style. Of course this doesn't bother me when I'm building the rocket (suddenly simple is good) and when I'm flying it (I'm only looking at the engine nozzles to judge my direction anyway).
Theme use is good! Fits well with the gameplay too!
Over all- it's almost like two games glued together, where one is visibly stronger than the other. The on-planet part drags down the great build-your-rocket-and-fly-it part a bit. Luckily, I tend to focus on the good!
Keep it up!