Nice video, Gideon!
Keebo's Quest actually uses allegro5.js, a little shim I wrote to overhaul allegro.js with Allegro 5 functionality. I made it a stand-alone library in the middle of Easter Hack. It is a work in progress that will likely never be finished, as it has a lot of bugs.
As for Firefox and CPU usage, I agree with bamccaig--it sounds like a Firefox issue. Which version of Firefox are you using?
- Draw primitives (arcs, circles, rectangles, triangles, lines, and filled versions of each)
- Load and draw images (drawn normally, rotated, scaled, and partial versions)
- Load fonts and draw text (filled and outlined versions)
- Interface with the keyboard (check if a key is pressed or released)
- Interface with the mouse (check if a mouse button is pressed or released; get X, Y, and Z axes; and show and hide cursor)
I will add loading and playing of audio files soon.