The core game mode works by passing URLs with another player over some kind of messaging service (e.g. Discord, WhatsApp, and maybe even post?). There's no time limits here, you just exchange drawings and guesses at your own pace, sort of like correspondence chess - that's what I mean by "async".
What's truly cursed is that this mode doesn't rely on a server or database: drawing bitmaps are compressed directly into each share URL. The "live" game mode (for 3 or more players), being a bit closer to a traditional "Jackbox"-style experience, does have a real backend though.
If you're curious, the tech stack is SolidJS, Astro, and Cloudflare Durable Objects. Something even more cursed: every pixel in the editor is actually its own <div>. This was originally a joke that went way too far, but I never got around to switching to something canvas-based and performance remained... fine?
It's designed for phones first, so apologies if you're on a desktop browser - it'll still work there, but there's currently a lot of unused horizontal space.