1125899906842624 (rileyjshaw.com)

When I read the title, I dreaded opening the link, half expecting it to be another 2048 clone with a ridiculous target! And boy was I right! :(

The target number is 2^50, and the grid is 64x64, so I think this should be fairly easy to beat if you ignore the fact that it'll take about ten million years at one move per second.

The font is out of place when you reach 128..