#9: Doom | 20 Games Challenge

I enjoy first-person shooters, but I can't say they're my favourite genre. I got very bored while doing Doom and simultaneously very excited for my Game 10, Portal. This is probably one of my weakest clones, and I will definitely refine it a little to give it some soul before I finish the 20 Games Challenge. Still, Doom was useful to refine a few systems and look into collisions in first person shooters, so a big win for me.

• Simple first person controller: Walk, sprint, strife, jump, shoot
• Single room with enemy AI based on Behaviour Trees
• Two enemy varieties: Shooting on ground, flying melee
• Two guns: Hit-scan (raycast based) and projectile based
• Pickups: Ammo, health
• Basic inventory system to switch weapon on the go
• UI to visualise ammo and health

Potential to expand with:

• More weapons and enemies
• My own custom 3D models
• A proper level inspired by the original Doom

Assets: My own, but very primitive!

What is the 20 Games Challenge?

In early 2026, I found out about the 20 Games Challenge. It's a fun challenge designed by SDG Games to recreate 20 games in an engine of your choice. The premise of the challenge is that, by copying a masterpiece, artists often gain a deeper understanding of the fundamentals behind their craft. This can also apply to game developers and game designers.

I was sceptical at first, but as someone who's obsessed with figuring out how things work, this challenge had some huge appeal. So, in March 2026, I decided to give it a try: I'd attempt to recreate 20 famous games in about a year, all in my favourite engine – Godot!

The 20 Games Challenge is fairly guided for the first 10 games, then free for the rest. Each level requires you to complete a set of steps in a vertical slice to consider it done. If you want to attempt it too, you can see options for the first 10 levels on this page.

My challenge list:

1. Pong
2. Jetpack Joyride
3. Frogger
4. Asteroids
5. Pac-Man
6. Super Mario Bros.
7. Worms
8. Crash Bandicoot
9. Doom
10. Portal ----- HALFWAY MILESTONE - FREE CHOICES FROM HERE -----
11. Minecraft
12. The Binding of Isaac
13. Lemmings
14. Guitar Hero
15. Metal Gear Solid
16. TBC
17. TBC
18. TBC
19. TBC
20. The Sims