A few of the weapons and powerups have been altered:
Fist
Attack speed is slightly increased, both with and without berserk
strength.
Chainsaw
Now three times as powerful as before, the Chainsaw also drives the
wielder ahead whenever it is used.
Pistol
The pistol is now more accurate and twice as powerful as before, making
it a viable weapon in a pinch, although not ideal.
Minigun
Accuracy is greatly reduced, making the minigun more of a close-range
weapon. It also takes a moment to get up to speed, so the initial shots
are slower, albeit more accurate.
Rocketlauncher
In addition to their explosive effect, rockets leave a deadly patch of
flames for anyone foolish enough to remain in the area. These flames
can injur the firer as well, so beware!
Grenadelauncher
In addition to their explosive effect, grenades explode into a spray of
shrapnel that can bounce around a room. Unlike the rockets' fire, this
shrapnel does not harm the shooter.
Freezerifle
This new weapon is similar to a plasmarifle, but fires slower for more
damage per shot. It will freeze anything in its arc, but look out for
ice-resistant enemies!
Cryo-railblaster (Railgun replacement)
The railblaster is a powerful single-shot gun firing frozen slugs that
penetrate multiple targets with ease. The first target in each slug's
path will also suffer an icy detonation. The slug will pierce armor
unaffected; the explosion will not. You can fire the railblaster at the
ground to "railjump," but be careful not to freeze yourself!
BFG9000
The BFG is mostly unchanged, but the projectile leaves tiny explosions
in its wake. They're probably not enough to kill anything, but they
will wear you down if you run forwards while firing.
BFG10k
The 10k's rate of fire is reduced, and its hitscan was changed to a
projectile. Each shot eats twenty cells instead of five.
Berserk pack
Once you switch to fist, you'll run 20% faster and jump twice as high.
Picking up berserk won't automatically switch to fist, though.
Fury
Bite
Firebreath
Additionally, all weapons switch twice as fast, unless the server has
the "sv_cemp_nofastswitch" CVar set.