The Blue Sun Mod

[R@S]

In HPW, they will only use high poly weapons, it has 10 levels.

The Boot camp uses all types of weapons, but each level increases their range and deadliness. It has 15 levels.

EoW, as the name implies, is a chronological setup, from older to newer. It has 22 levels and you gather points to get a reward. The more enemies you choose at each start, the more point you'll be rewarded resulting in better rewards.

There are some other minor differences, like in Boot Camp you can choose which pistol you get at the start. There are others, but can't recall right now, it's getting late...