@local-minimum Thanks for those interesting suggestions!
The reason planets light up was that an early design idea was that players could click on planets to see what resources the planets contained. You're right that changing the cursor when you hover over them is a bit of a useless holdover now.
Making the game real time would have saved clicking, but also made the game much more complicated to produce. For example, having to code logic for if you meet an enemy ship in between planets. I also found turn-based much easier to model, although I might try make a real-time game for a future Ludum Dare.
Losing ships isn't the end of the world, but it does mean losing all your orange cards (which can be a significant problem) and accumulated resources. More resources = greater ability to use a planet-killing weapon against Earth (ie the ultimate goal). Additionally, it sends you back to your home planet and forces you to skip a turn. If you lose a battle on your home planet, you lose the game. So if another ship happens to be beside your home, and they have a weapon, it's generally game over.
If you play with Stok, you get +1 line of sight from the start to allow for that "planning." Personally I don't need it but I did consider it would be useful for some players. Cards can also be brought to extend your line of sight, at least one of which is quite cheap. AI doesn't actually make use of extended line of sight information (it only looks at neighbouring tiles on the current turn, which is why pathing can be really stupid around blockades), so it won't buy those cards in the post-jam version. At least one of them is really cheap, too. So I'm going to stick by that this wasn't a bad design decision per say, more a fault of lacking a tutorial.
Great to get so much feedback :) Definitely useful and thought-provoking.