SiN is what happens when a 1998 first-person shooter looks at Duke Nukem 3D, Half-Life, and a cyberpunk comic book, then confidently declares, “I’ll have one of each.”

You play as Colonel John Blade, which sounds less like a real name and more like something generated by the ’90s Action Hero Name-O-Matic™. He’s a heavily armed security commander whose primary conflict resolution strategy is introducing bad guys to an alarming variety of firearms.

Your nemesis is Elexis Sinclaire, an evil biotech CEO who somehow manages to combine corporate executive, supervillain, and fashion model into one wonderfully over-the-top package. She’s basically what happens when a board meeting ends with, “Have we considered mutant soldiers?”

The story quickly escalates from “stop the bad corporation” to “why is everything exploding and why does everyone have extra limbs now?”

Like many shooters of the era, SiN embraces environmental interactivity with the enthusiasm of a kid who’s had too much sugar. You can shoot fire sprinklers, knock over shelves, shatter glass, trigger alarms, and generally redecorate every room with bullets.

The weapons are gloriously excessive. Assault rifles, shotguns, sniper rifles, rocket launchers… if it launches, explodes, or makes someone reconsider their career choices, it’s probably in your inventory.

One of SiN’s coolest ideas was its branching level system. Depending on how well you performed, or what spectacular mistakes you made, later missions could actually change. In 1998, this felt like wizardry. Today we’d call it “multiple outcomes.” Back then it was more like, “Wait… the game noticed?”

Of course, SiN also had the spectacular misfortune of launching just weeks after Half-Life, which is a bit like opening your neighborhood burger stand the same day someone unveils the world’s greatest steakhouse.

Despite living in Half-Life’s enormous shadow, SiN carved out its own cult following with frantic gunplay, tongue-in-cheek humor, interactive levels, and enough late-’90s attitude to power a warehouse full of frosted tips and wraparound sunglasses.

It’s loud. It’s cheesy. It’s unapologetically ’90s.

And sometimes that’s exactly what you want from a first-person shooter.