4Stack #67 — answers & breakdown

Friday, September 18, 2026

The sixteen cards in this puzzle were: Unreal Engine, Unity, Godot, CryEngine, Frostbite, RE Engine, Decima, Snowdrop, Havok, FMOD, Wwise, SpeedTree, DirectX, Vulkan, OpenGL, Metal.

The four stacks

Licensable game engines

Unreal Engine, Unity, Godot, CryEngine

In-house engines

Frostbite, RE Engine, Decima, Snowdrop

Middleware & tools

Havok, FMOD, Wwise, SpeedTree

Graphics APIs

DirectX, Vulkan, OpenGL, Metal

Want to try it yourself? Play puzzle #67 — archive plays don't affect your streak. Or jump into today's puzzle.