It reminds me a lot of Starglider 2. That was a great game from the 80s, which let you fly between several different planets to complete a set of missions. The graphics and gameplay were pretty amazing at the time on the Atari ST and the Amiga. One minute you'd be navigating around a set of tunnels deep inside a planet, and the next you'd be chasing whales in the outer envelope of a gas giant. It was some stunning game design and coding. I've not seen anything quite like it since.