The PlayStation Muesum has released a ten minute long video going through various parts of the game. Appraently, RE 1.5 had better graphics then RE 2 ended up having, the enemy A.I. was much smarter and the stories ended up being much different. Hit the jump for a little history lesson.
Eliza Walker was the original second character you would be able to play as rather than Claire Redfield. Eliza's and Leon's story never overlapped and there was to be more human characters that would help you out in the game. Marvin Branagh (the cop who was found near death in the beginning of the game) and Robert Kendo (the gun shop owner who couldn't tell the difference between a human and a zombie ... ) were going to be characters who would be more involved in the story to help Leon and Eliza (respectively) along with Sherry Birkin and Ada Wong (who was originally going to be a scientist rather than a spy).
At the one minute mark, it's revealed that William Birkin was going to sound like a zombified Arnold Schwarzenegger. Seriously, listen to that voice! As you watch the video, you'll notice that the levels had much more polish then what we ended up getting.
The zombies had the ability to sprint too. Not a full on run like the Crimson Heads, but I'm sure zombies that could sprint would have made the game a hell of a lot harder. Not only that, but the zombies are smart enough to actually crawl on their belly to get through small gaps. It's odd to see the zombies we ended up getting were extremely gimped versions in RE 2. A couple of new enemy types are also shown. At the 8:09 mark, a gorilla zombie is shown beating the shit out of Leon. Shortly after that, a Man-spider is attacking Leon in a lab.Check out the PlayStation Museum for a review of the RE 1.5, some screen shots and concept art and if you really want more info on this game, then I highly suggest picking up the Resident Evil Archives book. It covers all of the console games, give tons of back story, plenty of concept art and there's even a section about actual Biohazard incidents.
[*].disqus.comto your security software's whitelist.