Bungie took a weird turn in ME 3, whereby they doubled down on the whole 'Gears in space' feel of ME 2, but ended up throwing in some really naff level designs and missions whereby you were either bolted to a turret for a few minutes, or were retrieving items from a time-limited arena. Assumedly it was their take on Gears' Horde mode, but it flat-out sucked, making long-time fans feel like they weren't playing something designed by people that had sat down and wrote about the philosophical quandaries surrounding the Quarian/Geth organic/synthetic debate, and more like a mod made for the Call of Duty crowd. Mass Effect 2 had it pretty much spot on, giving you access to a range of Biotic powers alongside plenty of firearms, some special weapons with lower ammo counts, and the ability to deploy special attacks as you manoeuvred around the field. The only thing worth carrying over from 3 are the contextual kills where you could grab a guy over or around cover - all else either needs to be streamlined into its own take on the genre, or trimmed back to allow for greater strategy against any combination of enemies.