Now, without a dedicated coder(I do it but don't like it), that's not easy to achieve. I can say this though, I personally am working on a new gameplay element that will be present in the demo. With that in mind, assuming we can get 1-2 people more interested in coding, we would have every intention of adding even more elements in the full release.!
I believe, it is possible to add new gameplay mechanics, without even needing to write a single line of Ruby code, that's also relatively easy to build. One example that comes to my mind is that sneaking/disguise scene in Pokemon Insurgance. Since you don't have any Pokemon, you have to solve your problem (escaping from the evil guys) and what better way than disguising yourself and then sneaking out of their reach? That would also create interesting scenarios in later parts of the game, because you can give the player options: does he want to enter the building of the evil guys by the front door, where has to fight his way through hordes of Grunts, or does he rather take the secret path, disguise himself and sneak in, while avoiding being caught. Giving exclusive rewards for doing things differently also creates replay value, because the player wants to know, what happens if he takes the other route he didn't pick while playing the last time and all it takes are the sprite of the player character and a couple switches that control NPC behavior (and obviously you have to dedicate part of your level design for that purpose, but that's something coders don't need to deal with).
Now, that definitely doesn mean that I want you to build said feature into your game, because what gameplay you can use highly depends on what game you want to create and I certainly am not allowed to dictate you how to build your game. It's rather an example to illustrate what I mean with "new gameplay mechanics". :)