We could change the mechanics so it’s more of an action RPG.
Something more like the Elder Scroll series or the Witcher series.
Either melee combat or shooting spells.
If the Arduboy had an SD card and some more RAM, that alone would be enough to expand the repetoire massively, because every dungeon, monster and tileset could be shoved onto the SD card.
I know of a device that would fit the bill (I suspect @filmote and @Vampirics know which one I mean), but I’d be reluctant to move to a different system because it would feel like we were drawing people away from the Arduboy, or punishing those who don’t want the other system.
That’s just how turn based RPGs work usually.
One alternative would be to have a timed button press mechanic to increase attack damage, like in Paper Mario TTYD (one of my favourite RPGs because of its quirkiness):
But timed stuff is usually quite difficult to program.
In fairness though, it wouldn’t be the first time a game has drastically changed genre.
A lot of game series started off in one genre and ended up covering different genres with different games.
E.g. Final Fantasy had a spin-off called Final Fantasy Tactics that was grid-oriented like Disgaea.
The Elder Scrolls: Arena was nothing like Elder Scrolls V: Skyrim.
When I started learning to program the people at StackOverflow were always saying “use a library, don’t reinvent the wheel”.
I didn’t listen. Now I’m really good at inventing wheels because I learnt how wheels work internally and the sort of challenges involved in inventing wheels.
The moral of the story: feel free to reinvent the wheel, it’s fun and educational.