Franchise: The House of the Dead

The House of the Dead series, despite being featured quite prominently, has rarely been namedropped in SEGA crossover games.

In Sonic & Sega All-Stars Racing, Zobio and Zobiko's character bio shortens their debut as "HOTD EX" (despite games with longer titles such as Billy Hatcher & the Giant Egg and Alex Kidd in Miracle World not being shortened).

In Sonic & Sega All-Stars Racing, Sonic & All-Stars Racing Transformed, Sega Superstars Tennis, and Sega Superstars, all instances where a House of the Dead logo would be placed are instead swapped for a logo reading Curien Mansion in the same style as the series' logo.

Sega Heroes would be the game to finally break the trend, referring to the games by their title and with their original logo.

This may be due to the series being banned in Germany.

Many bosses in the House of the Dead series, from House of the Dead through House of the Dead 4 Special, are named after Major Arcana/trump cards (plus The Fool card) in a Tarot card deck.