Hello, welcome to my guide. I don't have all of these down to an exact science, one or two may still require a little trial and error, but I can point you generally in the right direction and update as necessary if we get it figured out more exactly.

I'm gonna attempt to lay out a very general overview before getting into specifics. The most significant fork in the story comes in Issue 6, when you choose to aid Scorpion or Nova, locking you into either the Villain or Hero route respectively. If you go the villain route, you do get the option in Issue 7 to pull a triple-cross by secretly siding with Nova after she's been captured, which forks off into 2 endings of its own. So these are both good places to have a save you can go back to if you want to try different paths from there without starting all the way over.

Other factors, dialogue or action choices before and/or after these forks can affect things as well, with the most noteworthy being if you decide to take the side gig or go to game night. Generally speaking, for the villain route it's better to take the side gig, and game night for the hero route.

The Road Untaken - Endings #1 & #2 (Quit)
These both count as one achievement, but there are some slight differences between the two. If you help Scorpion, you'll get an option to either leave the lair and quit, or stay and continue. If you leave, that's ending #1. If you help Nova, and when she asks for your help to take down Scorpion, you tell her you didn't sign up for this, you'll get a similar choice that night, to continue the story or quit. Quitting here is ending #2.

Endings #3-#6 (Hero Route)
There are 2 major factors in play here, and 4 total combinations that determine your ending. One is whether or not you romance Nova, and two is whether or not you become a superhero yourself. To opt out of romancing her, after she gives you your shield you can just tell her you're friends. To qualify as a superhero, it generally requires you to make smart calls and be good at fighting when applicable during the mission. Beat Antonio without her needing to intervene, use your shield against the mob of henchmen, divert the next group without having to fight them, initiate the feedback loop during the final battle. If you're trying to avoid becoming a hero, botch all of these.

Entrepreneur - Ending #3
Don't romance Nova, and don't become a superhero.

Super-Stan - Ending #4
Don't romance Nova, and become a superhero.

Superhero Hooky - Ending #5
Romance Nova, and don't become a superhero.

A Heroic Duo - Ending #6
Romance Nova, and become a superhero.

Endings #7-#10 (Villain Route)
This group of endings is a little harder to navigate than the hero ones. For one, Scorpion is harder to impress enough to romance, and two of these involve romancing her. You need to be smart, capable, ruthless, self-serving and career-oriented from the get-go here and take every opportunity to flirt. In the beginning fight with Nova, dodge, go for the knees, threaten the hostages. When she's pitching the side gig, tell her you work smarter, not harder, that you're in this for yourself, that you need more info before you'll agree to it.

On the side gig, use the other henchmen as diversions to sneak off, close the door to leave the stragglers behind. After you side with her, she'll eventually approach you to initiate the romance. For the non-romance ending(s), you can either choose to say you don't want it, or say you do and get rejected if you messed something up along the way. If you do successfully initiate the romance, keeping it as a casual fling or pushing for a more serious romance further affects your ending.

To trigger the serious romance, you need to question her about it as a possibility when it first comes up, and on your way to the final showdown after beating Antonio, press the issue and get her to explain her reasoning for why she wouldn't help you fight, agreeing that it was for your own benefit. When she asks if it bothers you that Dynamo might be dead, tell her you'll get over it. If you did everything right, in her office afterwards she'll broach the subject of a more serious relationship.

After the final encounter, as she's leaving the room and asks you to check on the computer, you might get a prompt to investigate it further ─ this is the point I'm least clear on, what exactly triggers this. I've had a couple of playthroughs where it skipped right past and this option never came up, but I think it helps if you aren't romancing her. Investigating it will give you the option to betray her.

Henchman of the Year - Ending #7
This is the easiest one to get. Just take the villain route and don't romance Scorpion, either by choice or by getting rejected, and don't betray her either.

Casual Villainy - Ending #8
Romance Scorpion and keep it casual.

Twisted - Ending #9
Romance Scorpion and pursue a serious relationship.

Lord Stanley - Ending #10
Betray Scorpion.

Endings #11-#12 (Triple Cross)
If you have a change of heart after helping Scorpion, and agree during Nova's interrogation to help her, it leads to these two endings. There's a single event that determines which you get, when you and Miss Dynamo are deciding whether to prioritize saving Nova or stopping Scorpion, so that decision is the perfect place to drop a save and easily backtrack to get whichever one you don't go for initially.

A Real Dynamo - Ending #11
Choose to rescue Nova.

Agent Stan - Ending #12
Choose to stop Scorpion.