So, scoping. If you ask me, in one month, it's probably more feasible to do a pure text-based adventure game.
Even a traditional linear graphical turn-based RPG is possible in a month if you keep it small enough (I've seen a few done in 48 hour game jams). The coding for these are actually not that complicated, and an experienced non-game programmer shouldn't have too much difficulty with it. The real time consuming part is the content creation. As well as making the actual assets, there's also map design, level progression, and gameplay to balance. This is what will probably prove the most difficult for someone without prior game development experience.