http://www.monkkonen.net/index.php

He's made a few games... and they're free! I recommend Wazzal, but the others look cool too, even though I haven't played them.
Wazzal is extremely short, but it's fun. It also has a lot of freedom to it.

Here are descriptions of the top two I recommend:
Wazzal
Wazzal is a quality freeware single player space privateering game. The game starts when you capture a ship to become an interplanetary pirate. The idea is to fly your ships in our solar system and accomplish missions while gathering a fleet of ships to fight bigger foes. Wazzal features an ingenious plot and beautiful 3d-graphics to ensure a premium gaming experience.

Notrium
You have crash-landed on planet Notrium. Your food supplies are running low, a pack of predatory aliens have got your scent. There are no more bullets for your pistol, your only weapon a handful of rocks. The night is coming, and you are desperately looking for wood to make a fire. Notrium is a game of survival.