This game is pretty awesome so far. I just spent an hour playing two of the starting levels, and had a blast! I really took my time to check out every nook and cranny, rescue every survivor, and gather every gem. I love that there's no time limit, except when you need to rush to rescue a dude before some terrible hazard takes him out!
If the first couple of levels are anything to go by, this will be quite the challenge to 100%, compared to the first game. There are a lot of long, unforgiving sections where you can get 1-hit killed fairly easily. I had a bunch of frustrating deaths while using the hungry suit, causing me to start lengthy sections all over again.
Regardless, I'm having a blast! If you liked the first game, definitely pick this up. If you haven't played the first game yet, what are you waiting for?
What a great series, now to get back to it!