Light-bot is a pretty fun, if simple flash game that I wrote about last year. At that time, I realized that by giving the robot recursive solutions, it was possible to reduce the commands needed to win from the previous bests of 160 or so down to 132.

Recently, Mark Beyers has found an even more compact solution.

Already a lot of people have worked on improving their score for this game. I wanted to either beat the best known score (132 commands) or prove it to be minimal by trying every possible solution for every level and seeing if it completes the level.

To cut a long story short, the solver managed to beat the best known solution for level 8, reducing it from 10 commands to 9 commands. The solution is complex and I find it difficult to imagine how a human could discover this solution without assistance from a computer.

Mark Beyers: Light-Bot in 131 commands

Here is my old video for level 8 (apologies for the sound):

Here’s Mark’s solution, which uses one fewer command. Level 8 starts 45 seconds in.