I was reading over on Rock Paper Shotgun about a flash game called One Button Arthur. Apparently it's the sequel to another flash game called One Button Bob which I have not played but I plan on doing that after I write this. (I went and played One Button Bob and I totally played it before but I'd completely forgotten I had) OBA is an interesting game. You control King Arthur going to look for Excalibur but there is a catch, you can only use one button to control Arthur. On each screen said one button does something different. It can make Arthur jump, run or just change direction.
Surprisingly it works really well. The puzzles are not super difficult but some can take a little thinking to make it through them.
It's a simple game to play and you should probably try it out. The link to Armor Games web site is bellow. They've made a lot of great flash games in the past and you should probably check them out as well.