Bio Prototype

Every few months, another Vampire Survivors clone crawls out of the primordial ooze of the indie storefronts. Most of them are content to copy the formula: walk in circles, hoover up XP gems, watch numbers climb, repeat. Bio Prototype, from developer Emprom Game, is not content. It looked at the genre’s core promise—the dopamine drip of watching a build snowball—and asked a genuinely dangerous question: what if the player built the snowball themselves, from scratch, wiring cause to effect like a mad scientist soldering a nervous system together?

The setup is pure body horror. You pilot a mutated monster—one of twenty-four playable prototypes—through top-down arenas swarming with grotesque experimental creatures. So far, so genre-standard. The twist is what happens between waves. Instead of picking “Magic Wand, Level 2,” you harvest, customize, and connect over eighty biological organs—brains, spines, nerves, tentacles, eyes—into automated skill chains. You’re not choosing weapons. You’re programming a creature to fight for you.

This is a visual programming language wearing a viscera costume. Emprom has taken the logic-gate thinking of games like Opus Magnum or Zachtronics’ engineering puzzlers and fused it to the frantic pace of an auto-shooter. The result sits in a strange, underpopulated niche: too cerebral for the “turn brain off” crowd, too twitchy for pure puzzle purists, and potentially compelling for the sliver of players who live in the overlap.

Now it’s arrived on Nintendo Switch, and the port raises real questions about whether a mechanic this fiddly survives the jump from mouse to Joy-Con.

• Organ-Based Visual Programming: The headline act. Over 80 organs act as nodes—triggers, conditions, effects—that you link into causal chains. “When a projectile pierces an enemy, trigger an explosion” is a sentence you build, not a perk you unlock.
• 24 Playable Prototypes: Each mutated monster brings distinct base stats and starting affinities, meaningfully changing which build archetypes are viable rather than just reskinning the same body.
• Emergent Synergy Engine: The real feature isn’t any single organ—it’s the combinatorial explosion. Chain loops feed back into themselves, and a well-tuned build produces screen-clearing bullet-hell cascades engineered by hand.
• Grotesque Pixel Art Direction: Detailed, deliberately unsettling biological sprite work that earns its “bizarre” descriptor and gives the systems a memorable face.

The Gameplay Loop

Here’s the tension at the heart of Bio Prototype, and it’s a productive one. The moment-to-moment combat is the dumbest part of the game—by design. You move. Your organs fire. You dodge. There’s little manual aiming, little skill expression in the arena itself. The auto-shooter chassis is a delivery mechanism, and it knows it.

The actual game happens on the pause screen.

Between waves, you drop into the organ editor, and this is where Bio Prototype either grabs a player by the throat or loses them entirely. There’s a monster, a fistful of harvested organs, and a blank canvas of trigger conditions and causal relationships waiting to be wired. The early hours are bewildering by design—or rather, by omission. Organs get slapped down semi-randomly, creatures flail, and the missing piece stays missing. Then, somewhere around the second or third run, it should click: this is a programming language, not a loot table.

That’s the revelation the design is built around. A loop—a projectile that pierces, which triggers a nerve, which fires a secondary organ, which spawns more projectiles, which pierce again. Suddenly this isn’t a survivors-like. It’s a feedback circuit that happens to vaporize monsters. When a loop fires correctly and the screen dissolves into a cascade of biological death, the satisfaction operates on a different level from watching an auto-leveled Vampire Survivors build do the work. Nothing was luck. It was engineering.

That’s the cleverness at the core. It converts the genre’s passive spectacle into active authorship. The “just one more run” compulsion isn’t fueled by RNG here—it’s fueled by “I have a better idea.” A run ends not because the player died, but because they spotted a flaw in their architecture and can’t wait to refactor it.

The Onboarding Problem

And now the knife. Bio Prototype is terrible at teaching itself.

This is the game’s defining flaw, and it’s not a small one. A mechanic this novel—a visual programming system most players have never encountered in a game—demands world-class onboarding. It gets the opposite. The tutorialization is thin, the UI is cluttered and unintuitive, and the game routinely fails to explain what its own organs actually do. Trigger conditions are described in language that assumes you already understand the system you’re trying to learn. Cause-and-effect relationships that should be visualized clearly are instead buried in menus that feel designed by an engineer for other engineers.

The result is a brutal onboarding friction wall. The players most likely to still be around are the ones who pushed through the opaque first few hours; how many bounced off before the click is the unanswerable question. Emprom built a cathedral and forgot to put a door on it.

There’s a second, subtler design gap: the game is light on meta-progression. Roguelites usually soften a punishing curve with persistent unlocks—a sense that even a failed run advances you. Bio Prototype leans almost entirely on knowledge progression. Improvement comes because you learned, not because your character did. For the target audience, that purity is a feature. For everyone else, the absence of a between-runs carrot makes the steep climb feel steeper. It’s a defensible choice, but it narrows the audience to those who find the systems intrinsically rewarding enough to be their own reward.

The biological pixel art is a genuine strength of theme. This is grotesque in the good way—detailed, squirming, wet-looking sprite work that makes the monstrous organs feel like actual harvested tissue rather than abstract icons. The aesthetic and the mechanic reinforce each other: wiring a spine to a cluster of eyes feels like the horrid surgery the systems describe. The retro presentation isn’t nostalgia for its own sake; it’s the correct visual grammar for a game about cobbling life out of spare parts.

The sound design, by contrast, is an afterthought. It’s functional and forgettable—basic effects and unmemorable audio that neither deepens the horror nor punctuates the satisfaction of a firing loop. A game with this much visual identity deserves a soundscape that squelches and pulses. This one just... plays.

Where the presentation falters is the UI, and it’s worth separating this from the art. The interface is the primary surface a player interacts with, and it’s dense, unclear, and hostile to newcomers. Critical information about organ behavior is either hidden or poorly labeled. Form and function are at war here, and function is losing.

Here’s the honest read on the Switch version: the port is where Bio Prototype’s UI sins come due.

On PC, the organ editor is driven by a mouse—fast, precise, forgiving. Point, click, drag, connect. The visual programming is fiddly even with a cursor. Move that same interface to a Joy-Con or the Pro Controller, and you’re now navigating a dense node graph with a stick or a d-pad, hopping cell to cell through menus that were already cluttered. The distance between “I have an idea” and “I’ve implemented it” widens noticeably. What was a quick refactor on PC becomes a chore of directional inputs.

The Switch’s saving grace is context. This is a think-y, turn-based-feeling puzzle game wrapped in real-time action—and that’s a strong fit for handheld, bite-sized sessions. Tinkering with a build for twenty minutes in bed or on a commute is arguably the ideal way to experience it. The portability suits the “test an idea, iterate, repeat” rhythm well.

So it’s a trade. You gain the ideal play context and lose the ideal input method. Touchscreen support in handheld mode would have been the obvious bridge between mouse precision and console convenience—if playing docked with a Pro Controller, budget extra patience for the menus.

Bio Prototype is one of the more conceptually ambitious indie games to hit the Switch this year. Emprom Game found real, untilled ground in an overfarmed genre and planted something strange and clever in it. When the systems click, this is a rewarding game—a puzzle box that rewards intelligence and experimentation with satisfying screen-clears, precisely because the player built the machine that made them.

But ambition isn’t the same as accessibility, and Bio Prototype confuses depth with difficulty of access. The wall between a new player and the game’s best ideas is made almost entirely of bad UI and absent teaching—self-inflicted wounds, every one. Fix the onboarding and this is a standout. As shipped, it’s a flawed but interesting experiment that demands players earn its best moments through frustration it never needed to inflict.

For those with the patience to teach themselves, the payoff is substantial. For everyone else, it’s a game that never bothered to introduce itself. Go in knowing which player you are—we recommend it only to the former.