These two games return you to a simpler time when light-guns ruled video games and tokens were the ONLY way to play.
The reissue of House of the Dead 2 is actually a re-release of the Dreamcast port. This verison contained both the Arcade version and what they call the "Original" version. In the Arcade version you just play though the game, as is. You can adjust the number of credits and the number of lives you get for each credit. Then you blast your way through the throngs of digital undead until you run out of lives and, subsequently, credits. While playing the arcade version, if you fail to achieve total victory the game aids you by granting another credit, which you can see in the options menu.
The "Original" version of HotD2 is similar to the Arcade version except that it starts with you in the trunk of the car, allowed to grab two extra items to help aid you in your mission against the decomposing digital zombies. These items range from extra health incriments, to extra lives, and even to extra chambers in your gun. To unlock them, in this incarnation of the game, you eventually unlock a "one-time-only" HotD2 mini game which allows you to earn new items. This minigame seems to be built on the HotD3 engine. It's an elevator ride down multiple floors, each a year in the HotD line from the release of this double game down to the arcade debut of HotD2. At each of these floors the door is pried open by zombies which you must dispatch. Based on your performance you are graded and can unlock better items.
There is also a boss battle mode in which you participate in each boss fight while being timed. The better the time, the better you score. It's nothing special and just one of those one-off attempts at adding a new level of replayability to the game for the home console audience. This isn't bad and is up to snuff with what you'd expect to see as an addition from an arcade game to a console release.
The graphics of this game are truly dated looking but it is a reissue and not a remake. They made no improvments to this title what-so-ever. I don't regard this as a bad thing. However, I have seen several people who railed and ranted about this game not getting a makeover. It wouldn't exactly be a faithful reissue of the old game if it had been given a next-gen face lift. The game has been lovingly preservered. This includes voice acting so terrible that it's one of the many points people made to making voice-acting a more respected form of acting. Yes, lines like "Dogs of the AMS...time they made a move" and some of the "My god" and "How can anyone do this" lines are so badly delivered they could make your teeth curl. But these horrible lines were there in the original release too. It helps to strengthen the nostalgia when those who heard them in the arcade or on the Dreamcast get that familiar pang as they hear them now.
HotD3, as I said ealier, was late to the US arcade market. As such, it isn't a game I have any fond memoires of playing in an arcade. However, it is a worthwhile addition to the House of the Dead bloodline. This railed shooter features something no previous zombie shooter has ever had: A SHOTGUN! It's about time a zombie shooter's default weapon was a nice little shotgun with a powerful spray as opposed to a small caliber handgun. The shotgun makes it easier to mow down hordes of zombies and the now permitted margin of error makes for a slightly easier time with boss fights when you must hit targeted weak points.
The game grades you on your shots, not only the speed at which you dispatch zombies but the accuracy you display in doing so. A single headshot as quickly as possible scores the highest while later kills which require more shots don't gain much at all. These skillful shots are tallied and your performance at the end of each level is graded on a scale from E (lowest) to S (highest).
HotD3 has what I regard as a fatal flaw, however. Reloads take a significant amount of time. This leads to a lot more frustration and what feel like cheap deaths as you attempt to stop a boss on the attack but ran out of ammo. Plus, the inherit weakness of the shotgun is that it only has a six shot clip so you run out of ammo often. "Reload" becomes a foul word through the course of the game.
This game's unique extra mode is a "time attack" mode. You are asked to play through the game with a very tight time limit. Accurate shooting earns you extra time. Taking damage also takes chunks out of your time. This mode also feels tacked on, but it's another typical additon to the game for the home console market.
All in all I would recommend every gamer from the arcade era should go out and buy this double pack. These are faithful resurrections and should trigger some profound feelings of nostalgia. I personally love the fact that motion gaming like the Wii has triggered a wave of new interest in the railed shooters, especially considering the old light guns don't work with any new HDTVs. Now, let's see if we can encourage Sega to bring back the Virtua Cop line and maybe make a new one.