Building a 10-Minute Alien Horror Game in Unity

So, I decided to make a short horror game where you wake up in your apartment, discover there’s an alien inside, and — spoiler alert — try to kill it with electricity. Sounds like a normal weekend project, right? Well, let me walk you through the chaos.

Why Only 10 Minutes?

Because let’s be honest, not every game needs to be a 40-hour epic RPG where you’re still collecting mushrooms in hour 12. I wanted players to have a short, fun, creepy experience — something you could play on your coffee break. Plus, it was meant to be a weekend project. Key word: “meant.” Thanks to my day job, it stretched to a week. (Game dev time is like dog years.)

Why an Apartment?

I could have picked a mansion, a forest, or a haunted space station. But nope, I went with an apartment. Why? Because small spaces are creepy. The walls are closer, the exits are fewer, and the claustrophobia is real. If you’ve ever had your Wi-Fi drop in a tiny apartment at 3 a.m., you already know the feeling.

Why an Alien?

Ghosts? Overdone. Demons? Classic, but predictable. Humans? Too real. Aliens? TERRIFYING. Honestly, aliens scare me more than anything else. There’s just something about the idea of a seven-foot-tall visitor in your kitchen rummaging through your fridge at night that feels… unsettling. So yeah, alien it is.

Pacing the Scares

I leaned on a few tricks: dark rooms, slow alien movements, and making the alien seven feet tall (because who isn’t terrified of someone that tall silently standing in a flickering doorway?). The idea was to keep the tension simmering instead of throwing jump scares every five seconds. Think creeping dread rather than cheap startle.

The Tech Stuff

• Engine: Unity
• Prototype Time: Supposed to be 2 days, took a week. Typical.
• Cut Features: Originally, the alien was going to lift the player up with telekinetic powers and drop them. Cool idea, but time said “nope.”

The hardest part? The alien’s AI. Teaching it how to stalk and behave believably was a challenge. On the plus side, I learned a lot (like: AI is basically parenting, except the child is 7 feet tall and wants to kill you).

Sound & Atmosphere

I used royalty-free SFX for footsteps, whispers, and ambiance, and pulled songs from Suno AI. Sound is where the tension really comes alive. Creepy noises in the walls? Check. Distorted whispers? Check. The alien’s footsteps echoing when you’re trying to hide under the bed? Double check.

Biggest Surprise

Mixamo. Seriously, that tool made rigging and animating so much faster than I expected. I thought I’d spend half my life crying over bones and keyframes, but Mixamo said: “Nah, I got you.” Bless.

Horror Design Lessons

At one point I actually ran a poll: should the game be in color or in monochrome black & white? The majority voted black & white. And they were right. Stripping away color made the whole thing feel more unsettling, like you were stuck inside a nightmare from an old VHS tape.

Advice to Fellow Indie Devs

Keep it short. Seriously. It’s better to make a 10-minute experience that’s tight, fun, and polished than a 2-hour mess that nobody finishes. Plus, you’ll actually ship the thing — which is half the battle in indie dev.

Wrapping Up

What started as a weekend project turned into a week of late nights, lots of coffee, and me side-eyeing my apartment hallway more than I’d like to admit. But I’m proud of how it turned out. Short, tense, scary, and just weird enough to stand out.

The game releases on Itch.io tomorrow. Come survive the night in my apartment — if you dare.