The better the game, the easier expansion packs can rely on a more-of-the-same approach (see Mass Effect 2 and Diablo III). Mystery of the Mooil Rig! is wholly effective in its series of nine missions, with objectives recognizable to those who have beaten Sunset Overdrive. Normally, I dislike being an errand boy in open world games, yet I’m happy to engage in fetch quests in Mooil Rig, because each quest is succinctly designed and retains the same kind of comedic storytelling found in the main game.

It’s hard to turn down assignments from one of the world’s more resilient and endearing quadriplegics. If you’ve played several hours of Sunset Overdrive, you’ll know I’m talking about Brylcreem. The absence of arms and legs didn’t stop him previously, and he remains the eternal optimist in the Mystery of the Mooil Rig. Now armed with a fortified exosuit, Brylcreem plays Colossus to the hero’s Wolverine, launching you toward key objectives, including a boss’ mouth. These scenes add thrilling forward movement; the more you hurtle at breakneck speeds, the more you want to keep going.

Add-ons to open world games either expand the maps with a new landmass (e.g., Burnout Paradise’s Big Surf Island, Forza Horizon 2’s Storm Island) or conjure up new experiences within the current city (e.g., Watch Dogs: Bad Blood). The Mystery of the Mooil Rig opts for the former, with a sprawling oil rig primed for more perpetual grinding. It’s an overly intricate off-shore base littered with life rafts, barges and other tiny landing points to help you avoid the water. With the exception of one occasionally lethal undersea creature, spending time in the ocean isn’t a hazard at all. Like an energy drink-addicted version of Jesus, this expansion capitalizes on the main game’s speedy methods of unaided water traversal. Whether you’re on or near the rig, the biggest rushes come from stringing together movement combos as you make your way to your next objective. The addition of two new water moves--a deep dive and an eye-catching high-flying uppercut--mean you can maintain movement combos for hundreds of yards in watery areas within Sunset City, not just the Mooil Rig. The upper cut--oddly named ‘Water Slam Bounce’--looks like a water-based Shoryuken, although I was unsuccessful in using it to attack flying foes. It’s more practical as a method for reaching elevated parts of the rig.

If I were to describe Sunset Overdrive’s look and feel to someone who knows nothing about Insomniac Games’ latest hit, it would be ‘bubblegum punk’. The closest aesthetic relation I can come up with is Crazy Taxi, but even that Sega classic didn’t saturate its visuals with this much fuchsia and neon green. Couple that with Sunset Overdrive’s grind-intensive gameplay. If it’s a railing or some semblance of a railing, you can grind on it. If it has an edge, you can grind on it. Somewhat like the adrenaline-fueled action film Crank, suspending forward movement often results in death. These situations are diciest when you have to protect stationary objects from invaders--it forces you to get creative with nearby grind points. Provided you mix up melee and ranged attacks, you’d be surprised how long you can survive going back and forth on a 50-yard railing.

Those who love Sunset Overdrive already know how playing well creates a feedback loop within seemingly chaotic combat. Having a sliver of health is seldom a cause for concern, because you know that firing another explosive teddy bear is likely to yield a health pack, along with a high body count. The missions in the Mystery of the Mooil Rig are seldom short of such moments, so surviving them is all the more gratifying.

Insomniac’s writers for Sunset Overdrive exude the chops of a revered, decades-old comedian, one who never laughs at his own jokes and knows to keep quips short and sweet. That includes avoiding the sin of over-explaining a punchline or the myriad pop culture references throughout the main game and this expansion. Even with a boss sporting multiple tentacles, the script wisely avoids hamfisted nods to Japanese erotica. Like the multi-generational appeal of Looney Tunes animated shorts, the Mystery of the Mooil Rig namedrops cultural allusions that many adolescents today won’t pick up on, like a certain Alfred Hitchcock film with cross-dressing. One of the most memorable missions is a fetch quest for the versatile ‘director’ Alan Smithee, whose name has been attached to many edited-for-TV movies dating back to the 1960s, a Metal Gear Solid trailer, and numerous voices in games like Eternal Sonata and Street Fighter X Tekken.

For all the risks Sunset Overdrive takes with its vibrant art direction and intuitive level design, the Mystery of the Mooil Rig is a fundamentally safe spin-off. It’s impressively consistent with the main game, and enough that relearning the controls takes no time, even if you haven’t touched Sunset Overdrive since launch week. This user-friendliness leads to tight, concise story mission playthroughs that will be familiar to fans of the main game. It’s not to say these objectives are easy. They’re just short, a result of Insomniac’s talent for creating scenarios trimmed of fat and devoid of filler.