One Must Fall Cameo's:

Epic MegaGames loved to make different characters and things from some of their games make guest appearances in other games, and as such OMF2097 appears in a couple of other games. The games I know has OMF references is: Jazz Jackrabbit 1, Jazz Jackrabbit 2, Tyrian.

Tyrian

In tyrian, you can pickup a Data cube with a message from Steffan. Recorded here.

Datalink from Steffan.

Jazz Jackrabbit 1

In certain maps various HAR's from OMF2097 appears as backgrounds. These should be as follows: (If anyone could get me screen shots from the other ones than Katana it would rock!)

Ep 1: Katana (Diamondus)
Ep 2: Jaguar (Technoir, Secret level)
Ep 4: Shredder (Nippius)
Ep 5: Pyros (Marbelara)

Jazz Jackrabbit 1 - Katana Cameo in Episode 1 (01)
Jazz Jackrabbit 1 - Katana Cameo in Episode 1 (02)

Thanks to Jai Robinson for sending these two pictures!
Jazz Jackrabbit 1 - Jaguar Cameo in Episode 2 (03)
Jazz Jackrabbit 1 - Jaguar Cameo in Episode 2 (04)


Jazz Jackrabbit 2

The katana also appears in a few maps in Jazz Jackrabbit 2. Like "Weird Science" in episode 1. Thanks to FraceR for the image :)

Jazz Jackrabbit 2 - Katana Cameo in Episode 1