Chex Quest 3

From Doom Wiki

Chex Quest 3 is a beta version of the last entry in a series of Doom-style promotional games included inside selected Chex breakfast cereal boxes. It has the same backstory and basic gameplay of the earlier Chex Quest games.

Being a beta version, Chex Quest 3 was never officially released in boxes, although the developer put up the game for free download on their website (now defunct), along with a blurb about an upcoming Chex Quest 4 that was never finished. The game is complete, though, and no obvious bugs are apparent.

In addition to the same wacky gameplay from the first two games, Chex Quest 3 includes new weapons, such as a clone of the super shotgun from Doom II, and several new monsters. Overall, it is very similar to Chex Quest and Chex Quest 2.