I would have a Weapon called a "Cloud Burst", which would produce a cloud that would follow you around the level and attack any enemies near you by raining acid rain on them. And on a fully upgraded weapon be a major storm system where they get the works. Lightning, acid rain, strong wind, etc.

The second weapon would be a "Veginator", where you use seed ammo produces a different killer maniac Veg every upgrade. Spinach, Cauliflower, Swede, turnips then the dreaded BRUSSELL SPROUTS!

You forgot CARROTS!!!!!
How about Ratchet's very own ability to use the FORCE-- foce gloves! Original=Force push (low damage), Upgrade=Force Choke (High Damage), Final Version=Force Lightning (Instant Death).

Or a new move to use with his wrench. Like push and hold sqaure button to charge up your wrench and square again to release a spin attack. Then it upgrades and releases a tornado as well.

RYNO
nuff said

Yeah, I missed the Ryno. It should return.

Also, something like the Tesla Claw. I found it to be a very fun weapon.

I want the Spiderbot glove again. I loved that weapon.

They have the Visicopter instead, and to be honest, it looks ten times better.

Sure, the Spiderbot led to some cleverly hidden Platinum bolts, but I found it to be pretty useless. The Visicopter is the opposite, as it can fly, so there won't be any getting stuck and having problems getting over ledges and junk like that.