Having the Lite demo playable in the browser is a smart way to sell a template, since people can feel the enemy system before they open Godot. Putting weapons, enemies and waves in .tres files is also the kind of thing that actually makes a template usable, because you can swap numbers without digging through scripts.
One thing I'd look for as a buyer is whether ARCHITECTURE.md walks through how to add a new weapon end to end, not just where the files live. The five-minute Lite run with the project ZIP included is a nice touch too.
Looks like a solid Godot 4 starter for anyone learning survivors-likes.