Scratch

Then point your browsers towards http://scratch.mit.edu/projects/mgmir/323913

The game in question is called the LASER game.  Any level developer who makes playable levels will be included in the final release.  Just download the project, make your own levels based on the platform colouring scheme which can be seen in the present levels, upload the version with your levels, and post a comment on the original project.  It's that simple!  For example, SqueezyCheeseCake created several levels included in this release (you can tell which ones because I included his/her name in the corner of the levels they made).  I hope you make some levels in this game, and you'll get full credit for everything you do.  To be honest, I'm sort of desperate for developers to help me with this... 

Thanks a lot for your help making this into a great game!  With a huge amount of levels and developers, we may be able to get onto the front page!

-mgmir