Used rogue, and upgraded his speed every level. Upgraded weapon damage and armor health via blacksmith. Upgraded critical chance from Jewel shop only. Currently have over 2000 speed and 600 attack, and I can pull off at least 5 attacks before the enemy attacks back each with 700 or 1500 critical damage.
Beat the survival level by only using Reaper, Skeleton Level 3, and Level 1 Earthquake. Just use Earthquake when you reach level 5, 6 which should be at least 6-8 minutes in since the Reaper, Skeletons will kill everything. Then during the grind of time, just keep casting Skeletons, Reapers when they get low on health or if you feel like. You can take other skills but it's not completely necessary.
Not sure if anyone else has this problem but every once in a while a block is there but it shouldn't be. I click on the block and it just disappears and is replaced. Probably just a small bug or visual glitch.
The grains of sugar are realistic and are about the size of a pixel however since the lines you make are not completely straight the grains just keep getting stuck in the line itself.