Yeah the mountains were a bitch but I thought the MAKO with the geth was awesome. You knock them around, land on the, pump them full of lead, blow em up, it really felt like you were in a tank, or at least I felt that way.
I also liked the multitude of equipment. It didn't feel particularly like micromanagement because you only have to worry about 6 people, and if they don't use shotguns you don't give them shotguns. Simple. ME2 added ammo (which was explained away in the first game and then retconned and the reason they gave was crap. What happened to heatsinks?! My guns could kill get just fine a month ago. What the hell happened?!?) and made the game more focused, so focused, in fact, that there wasn't very much exploring. The things hidden were plainly hidden, your arsenal was downgraded, vastly so to the point of using only two different guns all game, and where you did go felt VERY scripted. In the first game I would go out to the ends of the galaxy, scan some asteroids, find an abandoned frigate, and find out it was filled with horrible experiments, the reaper crisis never weighing on my mind.
Bioshock went down a dark wrong path after the first one. The path of consumerism. They knew they had putty in their hands, how could they exploit it? I hope they lose many fans and customers for this and either rot or learn to make a solid full game that is enjoyed on its merit and not attempt to rely on it's afterthoughts.