It is free to play fast survival management game. Very challenging to play.

It is a free to play base building and management game that is active and casual. Completely themed from Fallout game series.

It is a free to play 2D Bullet hell MMORPG.

Free platformer and puzzles game. Hard to do.

It is a free to play car racing simulator. It has 4 maps and 6 car versions for free.

It is a free arcade racing game, give it a try.

Free to play realistic flight simulator for only WW1 era. Free to play is Limited to the Training campaign and Quick Play with only 3 planes.

Free to play endurance run game that might be cool to play for a while.

It is a free to play Harem dating game combined with an Incremental Clicker game.

It is a free to play complex flight simulator for the Russian SU-25 ground attack jet. Also you have a TF-51 trainer plane you can fly.