Clash On The Fringe is a set of pay-what-you-want rules for military space adventure. They’re designed for use with whatever figures you have.
Unbound: Endless War is a free print and play game for two p layers in which you build a map and attempt to take over a players’ bases. It’s a pay-what-you-like game.
Afternova is a free print-and-play game about collecting resources from a solar system after it has been destroyed by a supernova.
Star Trek: The Dice Game is a solo, print and play game in which you manages the crew of the Enterprise through various mission challenges.
Invisible City Games offers a free board game called Aliens vs Cows. The aliens try to abduct cows. The cows try to protect the planet from the invasion.