Shelly = The bullets of shotguns are called shells
Nita = In native american language, nita means bear
Colt = Refers to the revolvers he uses, which is called colt
Bull = His super and is appearance is based on a bull
Jessie = her name meaning means gift, maybe scrappy the turret is a gift by someone else
Brock = The ROCK in his name is the short for rocket
Dynamike = Portmanteau of Dynamite and Mike
Bo = he uses a bow
Tick = bomb ticks before they explode
8 Bit = The graphic on old arcade machines are 8 bit styled
EMZ = Electro Magnetic Zombie
El Primo = means cousin in mexican, maybe one of the brawlers is his cousin?
Barley = some of the alcoholic beverages are made of barley
Poco = a term in music, Poco allegro
Rosa = her appearance wearing a pair of boxing gloves with thorns is based on the plant rose
Rico/Ricochet = ricochet means bounce, his bullet bounces when they hit walls
Darryl = Double barrel, the shotguns he uses
Penny = a kind of money
Carl = Rhymes with cart, which is the mining cart he rides
Piper = Rhymes with sniper
Pam = means all sweetness in greek
Frank = short for Frankenstein
Bibi = means lady of the house in French, but I don't know how it fits
Bea = Rhymes with bee, which is what she shoots
Mortis = The name brings the meaning of the third stage of death, rigor mortis, it also fits his occupation as a grave digger
Tara = Rhymes with tarot cards
Gene = genie, it's his motif
Max = Refers to MAXimum speed
Spike = cactis are spiky, just like his appearance
Crow = he is based on a crow
Leon = chameLEON
Sandy = he shoots sand pebbles when attacking