My favorite web game is Captain Forever created by Jarrad Woods. The only problem I ever had was that I wanted unique weapons like chainsaws and lasers. So I decided to create Vector Space. The goal of the game is to build up your ship with the modules you find while trying to survive the waves of enemies.
You can check out the game at Game Jolt: http://gamejolt.com/games/shooter/vector-space/32126/
Any feedback would be much appreciated!