I think the main challenge here is getting people to play it repeatedly. The leaderboards is the only aspect that really keeps you motivated. I think having the ability to challenge another player to a "Grid Off" would be a good feature. Pick someone from the leaderboards, go head to head for the highest score.

I also think you should consider the time to solve in the score. That would motivate people to not only try to solve the pattern better, but to be able to do it faster.

Overall decent job. The execution of the idea is done pretty well, I just don't know that the concept is super strong. Adding a few things could make it better, but I understand keeping the scope simple and trying to get it out there quickly.