I don't know how you managed to do it in 2 weeks. It's amazing! A great basis for some big game. Are you planning to add any storylines?
As for the gameplay, I think it would be interesting to desing it more for the shorter sessions, something like "Into the breach", with a clear goal and different mechanics depending on the level. I imagine it could be a very cool and unique mobile strategy. But this is of course only one of the ideas. You can also make a second Stellaris out of it :)