There are some subtle differences between the two versions in the single-player campaign. The PS2 interface makes the game even easier, as enemies and other items of interest are prominently called out to you with bright square reticles in the earlier levels. You won't find these in the Xbox version, so you'll need to rely more on tracer fire to track down enemies. You'll also find that certain portions of the levels in the PS2 version have been simplified, with fewer pieces of furniture in rooms or certain doors and areas taken out entirely. The effects of these changes end up being a lot more minor than they might sound on paper. The interface between the two is mostly the same--the viewpoint offers a slight curvature, as if you're peering through tactical goggles. Raindrops will bead up and slide down your view, and as you take damage, your view will crack bullet holes and go blurry, if you're playing the Xbox version, or you'll see a static distortion effect (like Metroid Prime) if you're playing the PS2 version. These are pretty neat effects, if rather nonsensical.
The slightly curved view makes you feel as though you're wearing tactical goggles.
Lockdown makes more of an impact with its multiplayer modes. Both versions of the game offer two-player, split-screen cooperative, for both missions and simple terrorist hunts. You can play cooperatively online through Xbox Live as well, with up to four players. Both versions also offer team-based and competitive modes for up to 16 players. The PS2 version offers fewer competitive modes, including team deathmatch, the objective-based rivalry mode, and the CTF-like retrieval mode. The Xbox version of the game gives you two team deathmatch modes, retrieval mode, and conquest mode (in lieu of rivalry mode). The online modes in both versions work well, if you can find a fast server. We did notice some teleporting here and there, but for the most part the games we played worked smoothly, with immediate updates to rankings.
The Xbox version is more interesting than the PS2 version because of its persistent role-playing-game-like element, PEC mode. In this mode you create a character avatar, choosing from four different classes, including commando, medic, spec op, and engineer. Each class has different special abilities, with medics able to heal teammates, engineers able to plant turrets, commandos specializing in heavy weapons, and spec ops able to wield sniper rifles. While class-based shooters are not new, what makes PEC mode interesting is that as you play, you earn credits and experience. You can use credits to unlock new items, weapons, and armor. You'll also need credits to repair your armor and items, which are tagged with durability. Experience lets you gain levels, which in turn gives you skill points that you can assign to upgrade your weapon proficiency or other areas. What's interesting is that the wide variety of areas you can upgrade means more variety in player skill as you level up. As a medic, for example, you could put all your skill points into increasing your healing speed and ability, at the expense of improving your weapon proficiency. Another, more offense-minded medic might choose to do the opposite, gaining in gun accuracy and power while still retaining basic healing abilities. It takes a decent amount of play time to gain levels, and at this point, it's tough for us to judge how well these RPG elements are working. The concept is definitely interesting though, and you'll have fun deciding which upgrades to get. It's worth noting that if you don't want to participate in PEC, you don't have to; you can still play regular games of Lockdown online on the Xbox without worrying about running into another player 15 or 20 levels higher than you.
As you've come to expect from the series, Lockdown's presentation is one of its high points.
Rainbow Six Lockdown doesn't disappoint in its presentation. Each mission is introduced via a slick series of animated/narrated slides that provide context for the operation. You'll then be able to pick out your weapons and loadout from a menu. The menu screens in the Xbox version of the game look particularly polished, with animated cutscenes decorating the background as the game's memorable theme song plays. The in-game graphics are also very nice looking in both versions--you'll find yourself exploring fairly large areas and buildings. There are some hiccups with character animation, particularly if your AI teammates bump into one other as they stack near a door, but for the most part everything looks great and runs smoothly. You'll find a decent amount of voice acting in the game as well, and the cutscenes attempt, for better or for worse, to give each character some personality. There isn't much music in-game, but when the score does strike up, it adds a good deal of atmosphere to a soundscape dominated by orders, yells, and crisp gunfire.
Lockdown feels in many ways like a top-40 pop album. All the polish and the basic elements are there to make it a great product, but it seems to lack a soul. You'll probably get some mileage out of multiplayer, which is as frenetic and enjoyable as you can expect from a game of this nature, especially co-op play. But the single-player gameplay doesn't hold up its end of the bargain quite as well. Tom Clancy's Rainbow Six: Lockdown rides that precarious border between tactical and arcade, and while still fun on the whole, it probably doesn't address either side as adequately as it should.