Ouch, I hope you just made a simple mistake somewhere, because I was eating infected civilians like peanuts.

It's ok, this is a useful answer so it can stay open for any others. Oh, and what double post

I didn't watch the credits so now I take it I missed a bonus scene or something. Good thing I'm playing the story again.

Ha, I thought I was still in the running for this thing, so I checked my stats and found that I had already consumed 30 civilians.
The first thing I did, was finding a crowded place, and tentacle devastator them. After that, I chewed up 10 survivors and continued my way as normal.

The Critical Pain is not half as useful as it was in Hulk: Ultimate Destruction. Tanks and Choppers are your most common heavy units which go down quick with the blade/thrown car, unlike Hulk, where they send mini-bosses (the Hulkbuster Destroyer, a Mech, roughly 5 times as big as Hulk, armed with loads of stuff to keep you occupied) to hunt you down. I only use it on bosses. In fact, I haven't even the ground version, only the aerial one.

Exactly, it's just bosses. With no Hydra threat or anything, Critial pain becomes useless in generic free-roaming.

I love the roundhouse kick with Muscle Mass (back + special). If you happen to kick a car with it, you can can it across an entire block, good stuff!