Very interesting looking game there.
Some observations from running it from an IT guy but not a developer of anything - yet;
1. It could do with a performance monitor/hud output showing FPS and renderer used.
2. It doesn't appear to use WebGL as there's no GPU usage showing on my monitor and even my little test games register on this.
3. It spawns 2 instances of the .exe plus a Chrome.exe over 45-50 individual threads, together these use around 950Mb of memory just into the second area.
4. The "defend all angles" bit is so hard I couldn't get any further to test how much this would grow by!
5. I couldn't find a way to exit the game.
6. On an i5-3450, performance was fine in game, the title screens looked slower maybe 15fps but hard to say without a monitor, this wasn't cpu or gpu bound though using 10-15% CPU (but no GPU).
You may know all of the above already, but I test/troubleshoot system performance in my work and look for bottlenecks so maybe it's just something I'm used to doing.