Hey there, just picked this up and am really enjoying playing around with it. Hoping to use it in a new prototype, so thanks for making it!
Just found a couple of small bugs in the latest build that I'm not sure if you're aware of: when using WASD to scroll the view, S moves down+right, and D doesn't seem move the view at all. Arrow keys are working fine, however. Also, when you ctrl+z to undo, it resets the selected colour to the first one in the palette rather than staying with what you previously had selected.
(While I'm here, the ability to draw 45 degree diagonal lines with the line tool would be a super awesome addition, but happy to put that somewhere else if you have a standard feature request process!)