[Suicide Junkie]

You could turn SE4 into a ground combat game.

- change the starmap backgrounds into dirt/grass
- make storm images that look like forests, lakes, rivers, etc.
- make planets look like cities
- make warppoints look like bridges, or mountain passes, or whatever.
- ships become tanks & APCs and Whatnot.
- units become turrets, infantry, minefields, etc.

for the planets;
- make each race in the game breathe a different atmosphere.
- have non-breathable planets provide only one facility space, no matter what.
- Have all the city images with flags on the buildings showing their allegiance.
- Then, when you capture a city, you have to wait 20 turns before the population settles down and accepts your rule. The planet's atmosphere gets converted, the flag changes to yours, and you can start to build stuff again.