Thanks to Elizabeth's ability to tear away the curtain between dimensions, Bioshock Infinite is the game where anything can happen. Well, in theory. In practice, it's a game subject to much the same tactical considerations as many of its shabbier contemporaries, where the concept of multiple realities serves as a fancier way of facilitating the introduction of bullets to skulls, fists to faces.
Don't know about you, but if I were Booker DeWitt, I wouldn't have limited myself to asking Elizabeth for stuff like ammo crates and cover spots. I'd have asked for all the Oddworld games Lorne Lanning never got to make, and a sedan chair carried by sentient Velociraptors, and a year's free rail travel, and a lightsaber autographed by Mace Windu. I'd have let my imagination run wild, in other words. Alas, letting your imagination run wild isn't something you can practically do when you're building something as finite and cost-intensive as a blockbuster videogame.
Still, Infinite's premise has left things wide open in terms of concepts and settings for downloadable content packs, of which there will be at least three. Let's put a few ideas through the wringer, shall we? Beware massive and wide-ranging plot spoilers.
1. Another trip through The Sea of Doors
Somewhat inappropriately for a videogame, but appropriately enough for a Bioshock videogame, Infinite is most memorable when it exposes your agency as a sham, a bankrupt illusion foisted on players by calculating god-designers. The Sea of Doors is the ultimate realisation of this, as Booker trots aimlessly between realities, asked to choose which path to follow yet reminded at every turn that choice is meaningless.
An extended tour of that serene, endless network of doors would make for a wonderful expansion, though it's hard to say how such a journey could be reconciled with the game's ending, already a bone of contention round these parts. One way of going about this and other DLC ideas would be to introduce a new lead character - or possibly, upgrade one of Columbia's NPC to protagonist status. I've got a candidate or two in mind...
2. Origins of the Songbird
Another of Infinite's more masterful touches is that you never actually get to fight the Songbird, as pre-release materials implied - a titanic aerial avenger born of Rapture-sourced biotechnology, he's simply far too powerful an adversary, one who must be tamed rather than conquered by way of a brilliantly symbolic little musical riddle. Having said that, the absence of a final showdown also means there's no opportunity to really get to grips with the creature's backstory, as has been the case for prior Bioshock nasties like Sanders Cohen. I'd welcome a pack, then, which takes the hints you'll discover in certain Voxophones and fleshes them out into a prequel campaign, either about Songbird or starring him a la Bioshock 2.
3. Booker's time with the Vox Populi
Another way of getting round the ending problem would be to set the DLC in the middle of the campaign, not after it, and the obvious candidate for this treatment is the section when Booker and Elizabeth warp to a dimension in which another, more politically minded Booker has led the Vox Populi to victory over Comstock's forces. This would also allow Irrational to re-address Infinite's sparky racial politics, which some felt weren't given the attention they deserved once the plot emphasis shifted to Elizabeth's origins and capabilities.