Risk of Rain Vanilla Enforcer
The Enforcer is another class that can easily be one of your first unlocks -he was tied with the Bandit for second class in my own game. You just need to kill all of the Magma Worm, the Wandering Vagrant, and the Colossus. And not in a single run, just in total.
He's also a lot more different from the Commando than the Bandit was.
His four moves are...
Riot Shotgun: Fires a short-range area-of-effect blast that does 160% base damage to all enemies within it. No cooldown.
Shield Slam: All enemies nearby are hit for 210% base damage, and are knocked away, mostly forward. (The hitbox is a little weird when it comes to enemies that are a bit behind you) While Shield Slam does not inflict the stun status per se, affected enemies will have attacks interrupted and take a moment to recover even after they've stopped sliding, with basically anything that's immune to stun being immune to the knockback. (eg flying enemies, most bosses) 5 second cooldown.
Protect and Serve: When Protect and Serve is active, the Enforcer moves slower and cannot turn (He will walk backwards if you attempt to turn), but Riot Shotgun fires 15~% faster and the Enforcer becomes invulnerable to most attacks if they don't manage to hit him from behind. 1 second cooldown after activation before you can exit the state, and 5 second cooldown after exiting the state before you can re-enter it.
Crowd Control: Lobs a grenade at a slight upward angle, which when it impacts with an enemy or terrain explodes for 250% base damage in a large radius, stunning all enemies inside the radius. If it impacts terrain at a shallow angle, it will bounce instead of detonating, extending its range. 5 second cooldown.
Since I got it in this run too, the Ancient Scepter transforms Crowd Control into...
Tear Gas: As per Crowd Control, except it inflicts Fear instead of Stun.
This is a subtle yet surprisingly useful change. As far as I can tell, there's nothing that's susceptible to Stun while being immune to Fear, and one of the main things the Enforcer tends to be striving for is getting himself some breathing room. Fear driving enemies away does that just fine, better than immobilizing them with stun in fact, albeit it does mean you should avoid using Tear Gas in a few situations Crowd Control would make perfect sense to use -eg when you're trying to finish off a lone enemy and Tear Gas would cause it to flee your strike radius, delaying the kill.
I actually had no idea Providence was susceptible to Fear prior to this video, and if I'd ever given the matter thought I would've assumed him immune to it! In fact, my recordings from here on involve a surprising number of examples of Providence being susceptible to status effects. He mostly seems to be immune to stun and knockback per se.
Note that Protect and Serve's block effect is really generous. The wiki will tell you that effects like electricity ignore Protect and Serve, but this is quite clearly wrong; what matters is where a strike is centered at. If it's behind the Enforcer, it does damage. If it's anywhere else -including coming directly above or below, where you would expect the shield to not block it- the Enforcer will ignore it while Protect and Serve is active. If you stand up against a wall or even with your back to a ledge, the vast majority of enemies are simply incapable of hurting you.
The hitboxes can catch you off guard, though, and some enemies you're probably best of treating them as ignoring Protect and Serve. Jellyfish electricity, for example, is absolutely blocked by it, but once they're sitting on you, spiraling directly atop you, their electricity will often end up spawning behind you and so hitting you, and so even though Protect and Serve blocks their attack it's a problem to treat it as protection from Jellyfish. Parents (The yellow humanoid giants) are another example that can catch you off guard -if they get in your face and throw a punch, it will go behind you and so hurt you even though the Parent is right in front of you using a melee attack.
What's particularly nasty is how many of the enemies that can bypass Protect and Serve in this way hit especially hard. Parents and Sand Crabs can take you from full to dead in moments if you let them, and so the process of learning when Protect and Serve is total protection and when it's not can get you killed really quickly.
The one other threat to Protect and Serve is Volatile enemies -the orange elite enemies that launch red rockets. If you don't move, those rockets tend to circle behind and hit you for damage just fine, and they hit hard. If a Volatile enemy is around, Protect and Serving against a wall is actually liable to get you killed. This, somewhat frustratingly, makes it increasingly risky to lean on Protect and Serve the deeper into a run you go, as elite and thus Volatile enemies get more and more common.
I was particularly lucky to not get a Magma Worm spawn in this run. The Enforcer is actually really good, able to fight hordes of enemies other classes would flee from without any real regard to stats or equipment, but the Magma Worm makes it extremely dangerous to even enter Protect and Serve. This is made up some by the fact that Crowd Control is splash damage and Riot Shotgun and Shield Slam are splash too, as the Magma Worm's 21 segments all take damage separately from area of effect and then contribute it to the Magma Worm's HP bar, allowing the Enforcer to potentially kill the Magma Worm shockingly quickly... but it's a race to kill it before it kills you, and it's easy to end up so focused on the Magma Worm some regular enemies kill you instead!
Outside the Magma Worm, though, the Enforcer is a reliably good class if you know how to use him. I especially appreciate that he's a slow, bulky sort of class that works; games frequently try to shoot for this archetype, and the vast majority of the time they either fail to make it appropriately slow and bulky or they succeed and the result is that it's garbage. It's a novel experience, and it's one of the earliest things to really impress me about Risk of Rain's design.