SlackBuildsOrg/games/chexquest3

chexquest3 (breakfast cereal themed FPS game)

Chex Quest is a game based on Doom, available in boxes of Chex cereal
in 1996.

Chex Quest 3 is a sequel to Chex Quest, created by the original
designer. It includes the complete Chex Quest 1 and 2 (as episodes 1
and 2).

To play the game, you will need a compatible Doom engine installed.
Currently, this means gzdoom, zdoom, or skulltag. You won't need any
.wad files from any of the Doom games, since Chex Quest 3 is a
total conversion.