I've been playing Mass Effect; I got it when it was 5$ on Steam. It's a crazy good game, that I've been enjoying a lot. The only complaint I have so far is the one that everyone has: the parts in the moon buggy are kinda lame. My only real problem with the driving segments are the parts where you have to climb a near vertical wall. It can be very frustrating.
Fighting with the vehicle is pretty funny. It's easy to kill anything at all, with negligible risk. Just poke your head around the corner, fire the cannon, then retreat back around the corner. Repeat until victory.
I had been expecting more stuff to do with the characters, I think the reason I haven't seen much of that is because I've been doing all the side missions, which doesn't advance the central plot at all. I'm working on the central plot now, and it's a very good experience. Having done all the sidequests, I'm crazy levelled up, and combat hasn't been difficult at all. Every once in a while I'll die, and it's always after I've forgotten to save for the past ten minutes. I actually think saving is what prevents me from dying.
To summarize: it's a good game, driving is kinda lame, and remember to quicksave every time you approach anything.