On September 29, 2001, The House of the Dead 2 was put on the infamous German index by the BPjS. For more information about what this means and to see a list of games sharing the same fate, take a look here: BPjS/BPjM indexed games.
The blood in the German version of the game is rendered green, but you can play through a level, shooting all of some gadgets to unlock red blood.
Some versions of House of The Dead 2 came with a free copy of Sega Swirl. A puzzle game described (by Sega) as "addictive". The documentation for Sega Swirl takes up over half of the Readme file included in HOD2.
House of the Dead 2 was voted #99 in the Top 100 Games of All Time poll published by Game Informer Magazine (Issue 100, August 2001).