The main idea is to create a Tetris game with missions.
Missions types:
  1. Achieve scores - basically, get the needed amount of scores.
  2. Achieve N lines - means break a certain amount of lines in the game.
  3. CustomField - create a custom field, with different amounts of cells, and different shapes of field. Concat it with Achieve scores mission.
  4. Achieve scores in time - get a certain amount of scores in some time(which should be configured)

Game Loop