Stacktris 2048

If you've never played 2048 before - don't worry, it's a super easy and almost perfectly addictive.
Drop and merge blocks of the same number together — 2 and 2 become 4, 4 and 4 become 8, then 32, 64, 128, 256, 512, 1024, 2048, and so on — to challenge higher number.