SimpleGUI missing
Many of these demos depend on SimpleGUI, which doesn't appear available in OpenFL.
Any plans to either substitute or port that over?
If I recall SimpleGUI is built on top of MinimalComps, which I think has already been ported. Any interest in porting SimpleGUI? There's a version circa 2011 that I have, which looks portable.
Unless there's direction on this, I'd take a stab at porting SimpleGUI and/or MinimalComps.
There were a couple versions of MinimalComps, though dated and only partially operational. As well, none were available via haxelib.
My port of MinimalComps is alpha, but coming together.
SimpleGUI will follow soon.
Once complete, these haxelibs will be an option if you're interested.
That sounds great and will certainly make these samples more complete.
Close, but there are still some issues across targets.
Pull request might be a week or so out for you to review.

Totally dropped the ball on this - MinimalComps is in relatively decent shape, but suffers some cross platform issues with web. SimpleGUI is there, but ceased at a RegEx exec call.
Intermediate monster head is cool, but all other demos experience unique issues.
Fractal Trees is broken, when you submit the form the app fails to render.
Shallow Water implementation seems distant, leveraging pixel bender if I recall - not sure when / if roadmaps will ever introduce that functionality.
So, I've lost some steam on this; however, I'd still like to complete this, even if only with partial functionality.