An RX 6600 paired with a Ryzen 7 1700. A mid-range GPU and a processor from 2017. According to one Steam player, that aging rig runs MOUSE: P.I. For Hire on Ultra without a stutter.

The game sits at #3 on Steam’s Top Sellers chart as of April 18, with 8,755 concurrent players still climbing. Not bad for a $29.99 indie shooter from Polish studio Fumi Games — a project that started life as a viral tech demo in 2023.

The Numbers That Matter

MOUSE: P.I. For Hire has accumulated 1,239 user reviews on Steam since its April 16 launch. Ninety-six percent are positive, earning Steam’s “Overwhelmingly Positive” badge. The praise follows a consistent pattern: the art direction, the voice acting, and — the detail players keep returning to — the optimization.

“Oozing with personality,” wrote one player with 6.6 hours logged. “I also appreciate a fantastic optimization and great voice acting.”

Another, running that RX 6600 and R7 1700, was more direct: “runs perfectly even on ULTRA settings […] VERY well optimised. also this game is GORGEOUS.”

When major releases routinely ship with performance problems, a game that simply works on modest hardware generates its own kind of momentum.

Cuphead With a Tommy Gun

Fumi Games built MOUSE around 1930s rubber-hose animation — the bendy-limbed, saucer-eyed style of Steamboat Willie and Betty Boop. Every frame is hand-drawn, rendered in stark black and white. GameSpot, which awarded the game an 8/10, called it “a visual marvel that’s always delightful to look at,” complemented by an original big band jazz soundtrack that nails the period.

The Cuphead comparison writes itself, but MOUSE is a different beast entirely. Where Cuphead is a boss-rush platformer, MOUSE is a first-person shooter with 2016’s Doom baked into its movement system. Double jumps. Wall runs. Dashes. A spinning tail for hovering. The roughly 11-to-13-hour campaign wants you moving fast and shooting faster.

Jack Pepper’s arsenal includes a pistol, shotgun, dynamite, and the James Gun — a Tommy gun that Kotaku’s reviewer called “one of my favorite video game guns of the year.” He can also heal mid-firefight by eating cheddar cheese, up to nine pieces at once. Weapons stretch and squash with rubber-hose flair when fired, and the slapstick violence lands somewhere between Doom and Itchy and Scratchy.

The detective mechanics are thinner. Clues pin to a corkboard automatically, and Jack intuits the next lead without player input. Both GameSpot and IGN flagged this as a missed opportunity. But MOUSE isn’t selling itself on investigative depth — it’s selling momentum, style, and the satisfaction of its gunplay.

A Split Verdict From Critics

Troy Baker leads the voice cast as Jack Pepper, a war-hero-turned-private-dick investigating a missing persons case that spirals into corruption and conspiracy across the city of Mouseburg. GameSpot praised Baker’s “sarcastic stoicism” as “both hardboiled and humorous.” IGN, which gave a more lukewarm 6/10, conceded the cast “do an admirable job with what they have” while criticizing the writing as over-reliant on cheese puns — every villain is a “cheeselegger,” every gag mouse-themed.

IGN also flagged the tonal clash between noir storytelling and the body count Jack racks up across the campaign, noting that he kills more people in a single mission than Philip Marlowe did across Raymond Chandler’s entire bibliography.

Fair point. But 96% of Steam players clearly came for the shooting, the look, and a game that treats their hardware with respect — not thematic coherence. Kotaku’s review went further still, calling MOUSE “one of the best first-person shooters I’ve played in many years,” despite flagging some late-game difficulty spikes and a handful of underwhelming late-game weapons.

A Wishlist Story Years in the Making

Before launch, the developers reported over 1.4 million Steam wishlists, according to iXBT.games — a staggering figure for a debut from an unknown studio. Fumi Games also confirmed the game would not appear on Game Pass or receive a demo version.

MOUSE: P.I. For Hire is available now on PS5, Xbox Series X/S, Switch 2, and PC at $29.99. No previous-gen versions. No shortcuts. Just the product and the word of mouth it earned.

Right now, that’s more than enough.

Sources