Great time waster...

Try this game. Its cool.

I gave up at level 22 - largely because I'd already wasted about 45 minutes on it. I may return later to see if I can get to level 30.

...later. Yippee. I completed level 30! That's it done.

You get to a point, somewhere in the low 20s of levels, where you get the hang of how the guy who wrote it thinks. And then you look for the least obvious route for one colour and find it quite easily.