A cool little KSP-inspired game! However, sometimes the rocket would rotate on its own, as if some unknown force affected it (it was neither inertia nor RCS), and it would reconfigure itself when hitting a wall. The screenshot below shows a configuration that helped me complete a level after running out of everything, using only gun recoil for propulsion.
As others mentioned, having an in-game tutorial would be nice, and the physics might need some tweaking.
Overall, this has some potential, great job on the entry!