Coldline Vol. 2

Attention spoiler: I sat down and designed the application flow how my app should work. Now, this was the easy part. I needed a way to model a branching phone menu system from a hand-drawn sketch, where the player navigates an automated hotline to ultimately launch an interception missile. The core abstraction i landed on was a directed graph: each GraphNode holds an audio key, a navigation mode, and a map of digit keypresses to successor node IDs. Two input modes drive all interaction — navigation, where a single keypress immediately routes to the next node, and code_entry, where digits buffer up and Space confirms, used for codes. A third mode, passthrough, handles dead-end informational nodes that auto-advance after their audio finishes with no player input required. Every node’s spoken text is defined in phoneGraphNodes.json with a stable audioKey that maps directly to an audio file, making it straightforward to record and swap voice lines independently of the graph logic.

I setup the project by creating my build chain (dyamic dev server via Bun runtime) and outlining a basic idea. Please note that the video below has been shortend in order to don’t spoil the story too much. I already implemented the Tutorial / Intro and title screen, including sound effects and animations for the intro. The game is intended to be fully immersive and lock you in for a couple of minutes. I will share more progress soon