After about an hour with the game my initial impressions are that it is actually pretty good and a great update that stays true to the 1nsane formula (if there are any other fans of that 11-year old game still around).
First off, this isn't an "offroad but on a track" kind of game like Dirt (which is a great game). Here they don't care how you get to a checkpoint and several of the modes actually encourage you to find the fastest path. And there are lots of gameplay modes, some of which I haven't unlocked yet. They have the traditional checkpoint race, the offroad jamboree (random checkpoints, find your own path), a "spotlight" race that is like a moving king of the kill, capture the flag and so on. These type of modes are one of the big things that made 1nsane so unique, so I'm glad to see them stay true to that while adding some new twists.
The driving is fast and loose, with your vehicle sliding all over the place in a fun way and lots of jumps to take. And they are nowhere near as fiddly or easily flipped as the ones in the first 1nsane. They added a constantly refilling nitro system here which I'm not sure if I like since it moves the game a bit more towards arcade-y than the first game, but it does seem to do the job and doesn't distract much.
From what I can see there are 18 different vehicle types to unlock in the career mode, with everything from buggies to rally cars, trophy trucks, Dakar-style support trucks, monster trucks, etc. You start out choosing one of three "team"s which gives you a vehicle (SUV, Truck or buggy) and a permanent boost to either top speed, acceleration or handling. You can unlock the other vehicles regardless of what team you start on. You are also gaining points when winning races to apply upgrades to your vehicles, in one of 5 broad categories like top speed or durability.
The AI doesn't seem overly aggressive, which is nice, but they are starting to put up a good challenge and beat me occasionally.
Visually the game looks pretty good, but not cutting edge. Better than I'd expect for a ninja release like this. It kind of reminds me of that game Fuel that came out a while back. The vehicles don't have the awesome dynamic deformation that lead to some crazy results in the first game, but they do lose doors and hoods and get banged up a bit.
One thing from the old 1nsane that I never expected to be in the new one (but is), is that the maps are actually a big wrapped tile so on those crazy competition types you can go fast in either direction and still make it to the same point.
Anyway, as a big fan of the original I like it.

I'm happy somebody else out there recognized the fun to be had with this formula and I will be playing more when I get time.