It's more mfin House of the Dead baby
Definitely doesn't try to innovate too greatly from the first game, but that's really because the first game was already a fantastic base to begin with. The fast paced zombie blasting is still here, there are still a lot of fun enemy types and encounters to learn, and there's still dynamic path switching to make replays varied and interesting. I do think the pacing is a bit weird here compared to 1 as there are 6 levels here compared to the first games 4, though both have roughly the same overall run time so levels feel shorter and it feels like there was more of an emphasis on bosses this go around.
My only gripes aren't really with the game itself but rather more my whole setup trying to play it. After liking the first game on Saturn so much I immediately went out to go find a Dreamcast light gun and the one I ended up getting is really jittery and not the most accurate. It still got the job done in the end, but somehow my third party saturn gun was more accurate than that thing. Also the CRT that I used had the picture zoomed in a bit so some parts like Heirophant's jumping attack were hard to counter due to how high up on the screen that mfer is. I guess both of those problems could easily be mitigated if you play the wii port or something, so it's probably better to do that. I think I still like game 1 just a hair more than this, but you really can't go wrong with either this series is awesome.