Nicely done! I recognise the game from the 3D course. :) I did a version of it last year too. I quite like these skilled-based games, and enjoyed having to figure out what was in front and what was behind. I also liked that collecting gold made you heavy, nice touch. Maybe you could have a star rating system where you get 1 star for finishing, 2 for collecting 50% of the gold, or 3 for collecting it all. Or somehow get some reward for getting the gold.
Two things I'd point out: the rotation feels a bit funny, like it's not centred in the rocket (maybe that's intentional?). To me it felt a bit strange, but got used to it quickly. And also, in the last level, going vertical was tricky because there was little 'preview' of what was coming. While it's nice that it raises the difficulty, it meant crashing 'out of the blue', if that makes sense, which was maybe a bit frustrating. I would keep the rocket a bit lower in the camera view for that level at least, if it was me.