First, good work submitting a game to the jam - that's always the hardest part. From your post on the discord it sounds like you want real feedback so I'm gonna go ahead and be honest. Please note that this is all my own personal opinion and you can disregard any of it that doesn't fit your vision.
There's not much of a game loop other than collect every single item - generally i'd be looking for more of a skill test (either interesting controls or puzzlers) but you could do also lean this more into an idle/clicker game direction by just giving incremental rewards; having the planets give you some bonuses like speed/pull radius when unlocked or activating a nearby warpstar to take you into the middle of a new zone (that felt pretty cool when I first stumbled into one but it'd be nice to earn it). After I unlocked the first planet and saw no real change in the game I was pretty ready to clock out, but I played XKCD's space explorer game for hours despite the main loop being exactly the same (partly because I love XKCD info-dumps, but also partly because every single thing you picked up made the game easier to play and felt like I was making actual progress ).
Another direction you could explore is the basebuilder approach where you have to spend resources to make resources. For example having to drop resources off at a planet; upgrading your ship to hold more; colonising new planets to have more drop off points, etcetc. You would need to have more resources that way, maybe slowly respawning natural ones and generators you could buy for planets, but that does start to become just a different game at a point
Presentation; You have multiple input options set up and the ability to skip dialogue, both of which are hurdles i've seen countless devs fall at. The little help/info menu is also something more jam games desperately need. That said, the in-game menu buttons could do with a way to control them without the mouse (since everything else in the game is playable through just keys)
The sprites are well chosen and the fog of war is actually gorgeous. I like that the border of the world isn't a hard stop but it would be good to not have it be less rapidly bouncy and to avoid spawning items outside of it. The story was also cute and well presented.
In terms of theme, it does fit pretty well. I like that you can't play while having the map open, and the fog of war prevents you going places you've already been which is very gratifying in a collectathon. Hell, the XKCD game I mentioned didn't have that and if it had I might've fully completed it! If you wanted to lean more into it you could definitely look at 4X games like Age of Empires, which you already have the fog of war from, and look at different things that make the exploration in them rewarding (fog of war usually hides information, which is why clearing it and keeping it open is a core part of gameplay)
Again, overall, you've done well here. I'll try and check out some of your other stuff in the future if you don't already hate me for this small essay :)