This is an HTML5 clone of Jelly no Puzzle, an excellent puzzle game that was released for Windows only. The game design and levels are taken directly from that. If you can run the Windows version I highly recommend it as it has a lot of great extra details.
How to play: left and right mouse button moves jellies left and right. When jellies of the same color touch they merge. Your objective is to unify all jellies of the same color.
Here's the source. To be implemented: