Update is out.
First impressions.
# Desperados is weird. He has two short-ranged wide-spread shotties with a delay in reloading, but he also has sliding animations with his guitar, so he's more maneuverable than the basic bro. His special is to summon his two mates and they play music, if any enemies are around they start dancing, before becoming confused. If the other two mates have enemies in sight, they will rain death upon them, otherwise they just stand around.
# Buffy is weirder. She shoots stakes which are like short-range knives of Machete, only at a slower rate. Her special is to throw holy water around, which scares normal baddies, but if Buffy stands in it she gets a halo over her head, unknown what that does (yet).
# Demolition Man is *hard* to play with. He fires a grenade like Chuck Norris, but it bounces weird and longer, and then it explodes in a cross-pattern. His special is a freeze-bomb which crawls across terrain and freezes enemies permanently. Not sure what they're trying with this one.
# Xena is fun. She has a sword, but somersaults all over the place yelling if you press Fire while moving left/right. It's her special where she shines, it's that circular blade which functions as her own personal sawblade! Indestructible, bounces off walls and tries to return to Xena. Her skill-ceiling is high.
# Seth Brundle is AWESOME! Besides making weird noises, he spits acid over everything, and can make short work of many mobs. His special is to teleport short distances, but his winning feature is to press Up while in mid-air, then he sprouts wings and hovers around. Acid death from above!
# Burt Grummer is the last bro to be unlocked. His primary is a Big Fuck-Off Rifle which makes Dirty Harry and Indy's guns look kinda feeble. His special is a sniper scope which appears on-screen and you move about, haven't tried it out that much to find out how it works.
# The campaign has been expanded. On the global map there are new 'challenge'-areas which are either 'one-life' attempts, or character-specific challenges. Some of these areas are marked on the map (with a 'C'), but others are 'hidden' and become available once the relevant Bro has been freed. There's one for MacGyver, another for Timecop, but it's the Indiana Jones-challenge which will have people pulling their hair out. Git gud with that whip, or git out! The rewards for completing the 'C'-areas is unlocking more power-up crates, but completing the character-specific areas unlocks cosmetic Flexes.
# The levels have been updated, as well as the enemy roster. Remember the big Bruiser with the Minigun? There are now Grenadier-Bruisers, as well as Kamikaze-Bruisers! The terrorists also have machine-gun nests, which are actually more deadly than the Minigun-bruisers. (Sadly Broforce cannot commandeer the gun nests.) There are also zeppelins, roller-trucks (don't get run over by them!) and more!
# NPCs that can be armed have been expanded. They gain levels for killing enemies, becoming more powerful. They're still made of cardboard though, so don't expect them to do anything major... though they may surprise you someday.
Conclusion? I'm maybe half-way through the main campaign, and I'm already submitting this as a 2023 GOTY. This was my 2015 GOTY, so I'm not afraid to do it again.