Cortex Command It's a very intricate and unique game. I have played many games and there is absolutely no game that comes even close to what Cortex Command does.
I can't even describe what the game is like because it's so unique and different but it's basically it's the most anarcho-capitalism game there is. The game revolves a lot of chaos, mind-controlling a bunch of clones/robots with a "brain" unit (it dies, you lose), collecting gold, and conquering territory. There are all kinds of factions to play as, such as car-crash dummies that had it's AI go rogue, stereotypical rebels (ronin), "space americans" (coalition), "space elves" (techion), heavily-armored mercenaries that use brute-force and a lot of flames (browncoats), zombies, robots, and more with their own weaknesses and strengths. You can shoot off helmets and armor off of people, have rounds and even grenades bounce off and explode your enemies instead with your modded power armor, get both of your legs blown off and make a heroic last stand before bleeding out by cooking a grenade then jet-packing and head-butting into your enemies, literally trample your enemies, or accidentally kill your units with flying debris from your own rocket that got shot down from across the map.
I found the campaign to suck and it doesn't feel complete at all, but it's definitely worth the price imo with all the other cool gamemodes like survival, wave defense, bunker breach, siege, skirmish, etc. especially since there are MANY mods. There are mods for warframe units and weapons, half life 2 stuff, dune stuff, Command and Conquer stuff, W40k stuff like necrons orks imperial gaurd and space marines, starwars mods, more zombies mod, zombots, space chaplains, medieval stuff, magical stuff, etc. You could play the game however you want, using one OP unit and OP gun, tunneling, bombing, spamming zombies, a few specialized units, using drones. I like to make my own themes and challenges such as playing on a map without much gold (actual gold which you can mine to get $$) so I have to make gold (gold is also currency) just from kidnapping enemies and scavenging weapons left over from battle with a dropship. Or you can just get $$ from killing enemies with a bounty mod, infinite gold from a mod of course, or a gold-mine structure that automatically produces gold which you or the enemy can mine so you can place the mine as a "flag point" as a very rudimentary player-made goal or just place it in your own base.
It is only optimized for single-core though, so if you have a monster dual-core CPU (use a i3-7350k over and i7 7700k, OC would be very beautiful for the dual-core) meant specifically for ARMA 3 or dwarf fortress like a stock i3 7350k at 4.2 GHz, you'll have a very good time. I can only recommend this game if you have a mid-tier computer with an ok CPU single-core cpu speed, mine is i5 4570k 3.2 GHz, 8 GB DDR3 ram but luckily graphics card doesnt matter much at all with this game. I bought the game several years ago and have easily clocked in hundreds upon hundreds of hours before it was even released on steam.