The Two Hour Warfames rules all play great solo. Most people who play them play solo. The only character you control is your “Star”. You don’t even have complete control of you squad\platoon and you have no control over your enemies.
Platoon Leader came out a little while ago. There are also other sets in the 5150 universe; Battalion Commander, Star Marine, Star Navy, Fighter Command, Carrier Command and the just released Hammer and Anvil. There are also RPG type supplements like Fringe Space.
I highly recommend these rules to anyone who plays solo.