A real solid and damn challenging mixture of card based strategy games with the core premise of Missile Command. Takes some practice but worth the effort. Linked video is a Let's play of the game.

RIVE is an intense and challenging action platforming shooter thing. Kinda like Blaster Master and Metal Slug but more unrelenting.

Absolutely superb shmup with some excellent pixel art and a well crafted difficulty curve.

Descent with permadeath and randomly generated levels. Plays silky smooth and provides quite a decent challenge. Highly recommended.

A real top notch and polished twin stick shooter that mixes in a few SHMUP style enemy attack patterns. A genuine challenge and a lot of fun in Co-op.

An actual honest to goodness great free to play game. Doesn't shake you down for cash and will, probably, make you want to throw money at them.

A nice adventure games that uses time travel to solve narrative puzzles and allows you to second guess your decisions. Unique characters for games too.

Sure it's a bit of a Asteroids/Geometry Wars mash up, but it's a pretty darn good one. Plenty of arcadey fun with the lowest price point possible!

My personal favourite tower defence game. This sequel adds a few refinements and gameplay tweaks along with improving the presentation and mode choice.

Easily the most profitable of all free games!