I bet you all know Happy Wheels game, this is crazy, mad and hilarious flash game. To describe it in a short it is racing game, it has funny characters and it involves overcoming tons of different obstacles and going through different scenarios.
Controls of the game are pretty simple, check screen below.
There are hundreds of popular videos on different sites, take a look at them below.
Author of the game is Jim Bonacci, he releases different updates very often, such as: bug fixes, new characters, new maps, new scenarios and things like that.
For create players game offers you opportunity to build your own maps, you can create your own little world and play there, if you are not into stuff like this you can still play ordinary basic maps.
Huge community is another great feature, millions of people play it on daily basis and you can share interesting stuff with them.