One Btn Bosses masters its simple premise

is true to its name: You need only one button to take on its chaotic, bullet-hell bosses.

Released Aug. 6 by developer Midnight Munchies, One Btn Bosses looks simple: On a 2D plane that’s mostly shapes and lines, you control a small spaceship (a tiny little dot, essentially, à la Asteroid) that automatically shoots its own bullets at the enemy, which simultaneously return fire — lots of bullets, deadly floor-is-lava-esque shapes, and lasers.

With its top-down view, One Btn Bosses puts everything on the same plane, restricting the ship’s movement as you try to dodge bullets. The ship moves forward or backward on a fixed rail in the shape of what’s usually a circle, square, or curved line. The one button impacts the ship’s movement. When you first start the game, the button changes direction; if your ship is moving forward, a button push reverses its course, which is helpful in dodging enemy attacks. But when you change direction, the speed at which your weapon spits bullets slows down.

As you progress, you’ll unlock different abilities; for instance, one early upgrade changes the button from a toggle that impacts directional changes to a one-time dash, which blasts you quickly through enemy bullets. There are also attack upgrades for weapons, like adding lasers to your ship, that, like abilities, can be swapped in and out between levels.

The art style and design is clean and polished. The gameplay is straightforward. The attack mechanic is restricted to, of course, one button. But it’s within those constraints that One Btn Bosses shines — it makes a single button a bastion of possibility in a world with lots of rules.

There are two modes to work through, the first of which is a short (four hours or so) campaign where you’re a grunt employee taking on literal corporate bosses who throw attacks at your ship. Quickly, you’ll unlock the second mode — the roguelite piece of the game, called Rifts & Developments, where you fight through procedurally-generated levels. You can switch between modes at any point, but your campaign unlocks don’t apply to the roguelite mode. That’s because One Btn Bosses’ roguelite is fairly traditional in its structure: You start with nothing special, and collect upgrades and abilities that change with each new round. It’s a fun way to try out a whole bunch of different abilities while blasting through fast-paced, truly challenging levels.

One Btn Bosses keeps things interesting level after level by slightly adjusting the bosses’ attacks or the field of play. One Btn Bosses is never slow, but it does start out simple, with enemies sending their bullets straight at you — no complex patterns to dodge. But it quickly ramps up to add more and more complexity, and less and less room for error. Sometimes, there’s a quirk to the level — there’s a curved line track that’s got portals on each end to mimic the constant movement of a circle without, well, being a circle. It takes a mix of reflexes and strategies to balance when you must push the one button; pushing it, like I mentioned earlier, slows the rate of the attack, which means you’ll need to fight the boss — and stay alive! — for longer. (The rate of attack slows any time you hit the button, actually, regardless of the ability that’s chosen.)

So what do you prioritize? Well, that’s up to you. I’m the anxious kind of player who’s always tapping the button to dodge the boss; I don’t mind staying in a level longer so long as I’m playing it safe. But the speedrunners out there will want precise pushes that keep the rate of attack up high to complete the level fast. That’s the beauty of One Btn Bosses — it allows for complexity and differing strategies even within the strictest of rules.

One Btn Bosses was released Aug. 6 on Windows PC. The game was reviewed on a Steam Deck using a download code provided by Midnight Munchies. Vox Media has affiliate partnerships. These do not influence editorial content, though Vox Media may earn commissions for products purchased via affiliate links. You can find additional information about Polygon’s ethics policy here.