Right, so new stuff.
The healing given by the powered cleave is pretty...useless, really. Even if you run into a group of enemies, you'll flat out lose more health than you'll gain. The fact that the cleaves bounce is nice, but using it for the healing is a completely futile endeavor. Go find some bread or meat, don't bother trying to heal with the cleave. Which is unfortunate, since I think the intention was to get the players to use the powered sword more, but giving it the healing power wasn't it at all. The bouncing cleave shots give it a big, BIG boost in usefulness since it's harder to waste a cleave now.
Honestly, without the Blazter's former healing powers, I kinda don't really use the powered form at all, since the spells and the charge shot is way to handy not to have at hand. I may just wind up personally modding it back into the Blazter and removing it from the cleave, really, if only to give myself a reason to use the powered form. It just feels weird to get rid of something that's been the Blazter's purpose for so long. And really, some of the enemies do a lot of damage, and being able to restore health at range helped balance it out. Without having a way to safely restore health, the damage the enemies do now starts to stack up very, very quickly.
Also, in regards to the enemies, mind changing the imp's spears back to blue? I never notice them coming at all now that they're grey. Actually, in general make the attacks colorful, so they don't get lost in the scenery. This tends to happen with the imp's shots and the steel duke's cluster shot, they aren't bright/colorful enough to spot, compared to the mage gunner's yellow shots, which are easy to see coming (which is why I somehow tend to run INTO the shots

). So far, none of the other new enemies attacks fall into this trap. I meant to say something about this earlier, but then Trailblazer happened.
The new subweapon, the OMEN, ties with the shield as the most fun to use weapon in the game. However, it and its powered form have 1 severe bug. If you jump/fall off a cliff and try to use it AT ALL, you'll deal about 20-70 dmg to yourself depending on how far you fall. And yes, I did try this in an empty room. Death message was "Cryomundus fell too far."
I do like what you did the knive's crash attack. Feels nice to have your own "Fan of Knives".
I was initially worried about you replacing the berserk, chainsaw, and radsuit with power-ups, but turns out for they're actually pretty useful. It gets a little weird tho when there's just multiple of them laying about and you can only pick up one. Are they permanent buffs or per-map ones?
I like the new enemies, the bomberknight I got a chuckle out of. I like the changes to the gunner mage, though the grenades don't seem to do much.