This game is the shit.
The first hour or so, I was kind of conflicted and I was certain the original was a better game. The combat was awful, Icarus was awful and the first mission just wasn't that good (and stuff like skill roll were gated, which is a bit stupid imo). But as I progressed I found the story missions to be getting better by the minute. And the NPC sidequests are very solid too, they're different enough from eachother as well. Next to that, the open world started to resonate with me. Its really solid and doing time trials in the open world rather than a separate mode is far better. Every time I play a few missions I come across and its not getting stale yet.
I also like the Gridnodes in particular, some excellent platform gameplay there. I never liked the combat in ME much, so the less enemies the better. Though its not that bad in ME2, as long as you're running and keep your focus up you can't be killed. Its just about finding higher ground, walls or jumps to one shot them from a different angle. I try to avoid straight up fisticuffs at all times.
I put about 10 hours into it, and am about two thirds into the story. I haven't found a single secret bag yet, lol. And have a lot of side missions to do. This will easily take 20 hours to fully beat.