This post is actually a bit late, with apologies, the build’s been up for a few days. Finally got laptops and Retina displays working by adding support for a smaller resolution (1080 x 720 in addition to the previous 1152 x 864) and tweaking my sprite code a bit. (“Sprite code?” you ask? Yeah, Demon started before Unity 2D was around, so I still use my own stuff. )
If you tried playing before on a laptop or Retina display and had trouble, give the new build a go and things should be much better.
One note: The resolution Demon runs at is chosen by Demon itself when you run it: it will pick the best of the two your system can support. No need to select it manually.
Here’s a couple of screenshots of the two resolutions (1152 x 864 followed by 1080 x 720):