Lockdown's biggest problem is its horrendous AI, which make the game a frustrating mess.
The gameplay has taken an arcade-y turn, and the game is actually easier because of it. You have a heartbeat sensor, which will detect enemies through walls and such, and this takes the tension out of it, as the previous games had. However, you don't have to use it, and I rarely used it. There's also an option where enemies will have a box around them, and you can thankfully turn that off, if you want. I found the game could get pretty hard later in the game, because I didn't really use these things.
The AI in the game is pretty frustrating, perhaps even broken. They might sometimes have decent tactics, and sometimes they do a lot of standing around, despite having a teammate killed right beside them. Early in the game, they're really dumb, no matter what the difficulty is. In fact,I don't find there's much difference between the difficulties, as the AI is barely improved. The AI does get ridiculously tough later in the game, as it can take 10-15 bullets sometimes, but in the beginning of the game, they can be killed in one shot. Your teammates also get pretty annoying, as they like to walk in your line of fire. Your teammates are also suicidal. Several times I've told them to throw a grenade to a certain spot, only to take cover behind a wall and throw the grenade at the wall. They occasionally don't follow orders as well. They sometimes won't throw a grenade, and will sometimes follow you around, even though I just told them to hold at a certain spot. Your teammates love to get in your face, and make walking through doors, or even a hallway a chore.
Another issue is the loading times. Every time you die or have to restart a mission, you have to wait through a lengthy load time. These last around 10-20 seconds or so, and it gets annoying if you die a lot (which will happen a lot, sometimes because of your teammates). There's also an annoying glitch which happens every now and then, but when it does, it's incredibly frustrating. I don't know how or why the glitch happens, but it shows your ammo clip as being empty even if you just reloaded, and when this happens, you can't fire,or even try to reload. This pretty much means you have to reload your last save, and it may even happen again.
There is also offline co-op, which is pretty fun, but suffers from the same issues. It also has an exclusive issue; there are no checkpoints in the missions. If you're at the end of the mission, and a civilian gets killed by accident or by a terrorist, you have to restart the whole mission, which is very frustrating. There is also online multiplayer, but I never got to play it, and I'm not even sure if people still play it. The shooting is solid,but the frustrating issues really make this game a chore to play.
The graphics are fairly decent overall. The characters have a decent amount of detail, more than in previous games. The animations are decent as well. The death animations look really good, as enemies die in realistic looking ways. Enemies disappear pretty quickly though,which makes the game feel more arcade-y. The environments are varied, and look pretty good, though some spots are a little weak. The weapons for the most part, are detailed, except for a few exceptions. The framerate occasionally slows down, especially in co-op. Overall,the graphics are solid, but have a few obvious wrinkles.
The sound is good, with good sounding weapons. The music is good too, at least in my opinion. The voice acting is good for the most part, but there are a couple cases of cheesy dialogue. Your teammates get annoying when they say "awaiting orders" or something like that with boredom in their voice. I did notice the sound would occasionally disappear, particularly during co-op.
There's a solid amount of content in Lockdown. You can buy weapons, cheats, and more from collecting intel. The campaign is fairly lengthy, with 16 missions. The co-op is solid as well, but suffers from some issues.
Story: The CG cutscenes look great, but the story still wasn't entertaining or interesting to me. They tried to add more personality to the characters, but they're kind of annoying. 5/10
Gameplay: The gameplay is still solid, but broken AI ruins everything. Your teammates love to stand in your way, and have you shoot them. You will die a lot, and to make things worse, you'll have to wait through lengthy loading times every time you die. Don't forget the gltich. 4/10
Graphics: Mostly solid looking weapons and characters mixed with decent animation. The death animations are great. Some of the environments look good, while others look dated. Frame rate occasionally takes a dive. It looks decent overall. 7/10
Sound: Fairly decent overall. Good sounding weapons and mostly solid voice acting, with occasional cheesiness and annoying teammates. The sound may occasionally disappear. 7/10
Value: Weapons, cheats and more to buy. A lengthy campaign and solid co-op. Of course, you'll probably be too frustrated to keep playing for long, due to AI, loading times, and the glitch. 4/10
Rainbow Six Lockdown is a frustrating first person shooter. Rainbow Six fans won't enjoy it much, as it has a arcade-y flavour to it. I enjoyed it when I first played it, but the more I played it, the more I noticed how broken the AI is. The gameplay is still solid and sometimes fun, but these serious problems really bring it down. Lockdown is not even worth playing.