Use number keys to select buildings and click to place them.
Numbers in top right are (from top to bottom): Money, Population, Injured Population, Infected Population
To run the game you need Node.js. You also need to use npm (the Node.js package manager) to install Socket.io and Express. Then run 'node server.js' in the main directory as root (or change the port the game serves on) and go to http://localhost/builder/ in a HTML5-capable browser.
A version of the game that has been updated since the jam is hosted at: