Personally, I feel the first game was hands down one of the worst video games ever made.  Yes, it had a good story that fit in with the series, and decent graphics, but the gameplay of it was horrible.  The original had many gripes that eventually made me scream so much that I was hoarse for a week, and left me with a broken XBOX controller.  Elixers barely existed in any levels, and defeated enemies rarely dropped health for you to slightly heal.  Enemies always blocked your attacks.  Stakes could get easily knocked out of your hand, which left your enemies ready to throw cheap combos at you as you tried to pick it back up, and if you knocked them down to pick the stake up, they'd always immediately get back up as you did.  It also had a poor hit detection system--- one time I staked a face down vamp about six times, AND HE STILL DIDN'T DIE.  I returned the game about a day later after buying it.

The second game thankfully fixes many of these problems.  Health packs are now slightly easier to find, and when you kill enemies, they will regenerate health more often.  Enemies also block far less, stakes don't get knocked out of your hand, and there's a nice button that lets you quickly pull out a stake to kill a vamp or demon, unlike the original where you had to take the time to equip it, which meant that an enemy would get a chance to recover before you could even kill them.  When you stake a face down vamp, it actually kills them.  Also, about the inventory.  People complain that you can only hold 5 healing items, while in the original you could hold up to 9.  I think that they're forgetting that if you did, this meant you could not have any support weapons--- in other words, no hellfire or holy water.  In this, you can max out your medpaks while still carrying plenty of hellfire and holy water(for a total of 15).  Also nice is the ability to use multiple melee combat weapons, since in the original, you could only use one at a time.

Character wise, Buffy and Faith have their usual Slayer skills.  Willow uses magic.  Xander, although you will also have him in combat, relies mainly on weapons.  Spike's main aspect is his strength, and Sid's small size makes him hard to hit.  One cool thing is that sometimes another character may fight with you--- for example, in the first level Buffy and Willow team up to battle a group of vampires, or in the second features Buffy and Spike fighting it out with zombies.  Bosses also feature some actual puzzles to get to their weak spots this time around, which thankfully aren't incredibly frustrating and easy to figure, as opposed to the first game's bosses which were just more fighting, which mostly had each one of them relying on this incredibly cheap tackle attack that always knocked you down.

Yes, there's still a cheap camera, and you do have to search through inventory midgame, but overall, Vivendi Universal has created a much better Buffy game than EA did(now here's hoping that there will be an Angel game with Angel, Spike, Illyria, Gunn, and Wesley).  I suggest if you have a choice between Buffy 1 and Buffy 2, get Chaos Bleeds and pretend the shoddy original never existed.
Personally, I feel the first game was hands down one of the worst video games ever made. Yes, it had a good story that fit in with the series, and decent graphics, but the gameplay of it was horrible. The original had many gripes that eventually made me scream so much that I was hoarse for a week, and left me with a broken XBOX controller. Elixers barely existed in any levels, and defeated enemies rarely dropped health for you to slightly heal. Enemies always blocked your attacks. Stakes could get easily knocked out of your hand, which left your enemies ready to throw cheap combos at you as you tried to pick it back up, and if you knocked them down to pick the stake up, they'd always immediately get back up as you did. It also had a poor hit detection system--- one time I staked a face down vamp about six times, AND HE STILL DIDN'T DIE. I returned the game about a day later after buying it. The second game thankfully fixes many of these problems. Health packs are now slightly easier to find, and when you kill enemies, they will regenerate health more often. Enemies also block far less, stakes don't get knocked out of your hand, and there's a nice button that lets you quickly pull out a stake to kill a vamp or demon, unlike the original where you had to take the time to equip it, which meant that an enemy would get a chance to recover before you could even kill them. When you stake a face down vamp, it actually kills them. Also, about the inventory. People complain that you can only hold 5 healing items, while in the original you could hold up to 9. I think that they're forgetting that if you did, this meant you could not have any support weapons--- in other words, no hellfire or holy water. In this, you can max out your medpaks while still carrying plenty of hellfire and holy water(for a total of 15). Also nice is the ability to use multiple melee combat weapons, since in the original, you could only use one at a time. Character wise, Buffy and Faith have their usual Slayer skills. Willow uses magic. Xander, although you will also have him in combat, relies mainly on weapons. Spike's main aspect is his strength, and Sid's small size makes him hard to hit. One cool thing is that sometimes another character may fight with you--- for example, in the first level Buffy and Willow team up to battle a group of vampires, or in the second features Buffy and Spike fighting it out with zombies. Bosses also feature some actual puzzles to get to their weak spots this time around, which thankfully aren't incredibly frustrating and easy to figure, as opposed to the first game's bosses which were just more fighting, which mostly had each one of them relying on this incredibly cheap tackle attack that always knocked you down. Yes, there's still a cheap camera, and you do have to search through inventory midgame, but overall, Vivendi Universal has created a much better Buffy game than EA did(now here's hoping that there will be an Angel game with Angel, Spike, Illyria, Gunn, and Wesley). I suggest if you have a choice between Buffy 1 and Buffy 2, get Chaos Bleeds and pretend the shoddy original never existed.