Little Worlds Interactive has released its strategic tower defense game, The Counting Kingdom on Steam Early Access today. What's interesting about The Counting Kingdom is that the main gameplay mechanic involves solving math problems to cast spells.
In The Counting Kingdom, players jump into the shoes of a wizard's apprentice who must stop a horde of angry monsters from destroying the castle towers in the kingdom by using spells, potions, and food old fashioned mathematics.
You can find the game on Steam, for under $10 or on the game's official website. Also be sure to check out the trailer to your left. The game works on Windows PCs and Macs. A mobile/tablet version is tentatively set for release this fall.