A bioluminescent horde-survivor. Move; the swarm comes; the light wins. Every level-up is a card draw, and the sealed card and the rift both stay shut until the arithmetic written on them is answered.
The pack suggests age 8 and up. The difficulty itself follows the player, not the age.

DEEPSWARM draws its questions from these parts of the curriculum. Which of them a player sees, and how hard the questions are, follows the player.