>>11845931
You can turn on stuff like Infinitely Tall Monsters in the compat options if you want to, as well as using the original hit detection (which makes melee less fun).
GzDoom doesn't really do demos (in the regular sense anyway), but as much as that sucks, it's a tradeoff I'm fine with making for the enhanced featureset.
After all, there's no vanilla Hideous Destructor or HDoom.