You are caffeine. A high-velocity roguelike FPS through a human bloodstream. Your survival timer only refills by killing — stop and you're metabolized. Every kill makes you faster. Every run rolls new weapons and upgrades. Reach the brain before he falls asleep. Players gave MAINLINE a 100% positive score. Released September 13, 2026. Top tags include FPS, Fast-Paced, Arcade, Roguelike, Shooter, Action, Stylized, Score Attack, First-Person, and Indie.
You are caffeine. A high-velocity roguelike FPS through a human bloodstream. Your survival timer only refills by killing — stop and you're metabolized. Every kill makes you faster. Every run rolls new weapons and upgrades. Reach the brain before he falls asleep.
Developed by Bakuevo · Published by Bakuevo
Player Review Breakdown
MAINLINE has about 2 positive and 0 negative player reviews out of a total 2. We'll add a detailed breakdown here when there are more reviews.
100%
positive of 2 player reviews
Full Game Details
From the Devs
YOU ARE CAFFEINE.
Injected into the arm of a human running on empty. Reach the brain before you are metabolized, and wake him before he falls asleep.
KILL ENEMIES. KEEP TIME ALIVE.
An unbroken kill chain and absolute speed — a super-adrenaline-max roguelike FPS.
Your survival time is 4 seconds. Killing enemies gives time back. Taking a hit drains it further. As metabolism closes in, your vision darkens and your heartbeat accelerates. There is no bar showing how much time remains.
THE MORE YOU KILL, THE FASTER YOU GO
You never stop moving forward through the bloodstream. Strafe around the vessel wall — slip past incoming fire and the clots blocking your path.
Every kill raises your speed. Then it is on to the next enemy. Keep killing and the acceleration stacks, your view widens, and the speed lines stretch out.
This is not a racetrack. It is a human blood vessel. The speedometer does not read km/h. It reads nm — nanometers. Tear through this microscopic world fast enough to rip your vision apart.
Every enemy carries a weak point inside its body. Finish one through the weak point and your magazine comes back whole.
NO TWO RUNS ARE THE SAME
Clear a stage, then take one of three cards. Swap your gun, or upgrade the one you have. You carry exactly one gun.
Magazine size, damage, fire rate, reload. These upgrades keep stacking even when you switch guns.
FOUR WAYS TO PLAY
Normal Stages, EX1, EX2, and Endless. Expected playtime: 1–3 hours. Your Endless record is carved into the Steam leaderboards. Run to the limit and take first place.
FROM VEIN TO BRAIN
Peripheral vein, heart, lung, aorta, blood-brain barrier, and the brain itself. Six chapters wear the color of the blood, shifting from dark venous red to the electric hue of nerves.
Adenosine receptors block the way. Platelet walls your rounds cannot pass. Clot lasers sweep the vessel. At the end of every chapter, a mutant guards the gate to the organ.
Fall and you restart the chapter. Every upgrade you stacked, every gun you held — wiped.
A LITTLE MORE EXPENSIVE THAN AN ENERGY DRINK.
But it will wake you up more.
STREAMING AND VIDEO
Streams, videos, whatever you want. Monetization included. Put one link to this store page in your description — that is the next injection. Appreciated.
Note: This game makes heavy use of flashing lights, strobing, and sudden color inversion. Players with a history of photosensitive epilepsy should take care.
