Planetary Annihilation is as ridiculous as you'd expect from a hybrid between Total Annihilation and Supreme Commander. Insanely hectic RTS battles take place in entire solar systems, with players wielding outrageous weaponry and even smashing celestial bodies into each other. It's still very much a work in progress, but if you want to engage with the Early Access cycle, you can save 50% on its inflated RRP via The Humble Store. As always, remember that you're paying for access, not a polished product at this stage, so only pay what you can afford to lose.
Thanks to BattleMoose87 @ HUKD!