I've only played the first couple of levels, but the second half of the first level confused me.
The hostage situation was great; my objective was clear, and I found it pretty fun to go through it with the rewind ability. But once I got past the tug boat, I got confused about where I was supposed to go. The jump from the first to the second platform was far enough that I didn't even realize I could do it. It ended up taking me a few tries before I actually did.
I couldn't figure out what to do from there, so I ended up just hitting the nearest boat with a truck and using it as a platform. It did feel cool, but also unintended. I still don't know what the actual end goal is.
Also, more minor point: the fact that you can rewind and get your ammo back is cool, but it's pointless if the ammo isn't finite. Perhaps consider limiting the amount of ammunition a player has.