I am working towards an important milestone of this project - a fully playable demo. It will showcase an entire prearranged battle to demonstrate the general gameplay. It will be fairly polished, with special effects and audio that I plan to purchase in large commercial packs. From there, it will just be a matter of going into full production on the rest of the content and features, like the hero classes, enemies, and areas.
I have been contemplating some of the design features...
Damage Types and Defense Stats
The damage types are: physical, fire, cold, poison, and arcane. All creatures tend to focus on one or more. I considered defense stats for all these, but as a player, it gets unnecessarily complicated quickly: "This creature has half the cold defense as fire, but my fire spell does x more damage, should I use that or poison at wait.. what was the poison defense again? It is a goblin, which is green, so is that more or less resistant to poison? Screw it, I'll just attack with fire and pretend it was the ideal strategy."
...So, instead, defense stats only will be physical and magical that groups all the elements into one. In order to create distinctions between the elements, some creatures in particular areas can be completely immune or resistant to one, such as fire. It ought to force the player to utilize different heroes at different areas, rather than just blindly grinding away on a select few.
Each of the player's heroes can wield an interchangeable weapon for basic attacks and passive bonuses. I considered having an inventory system with procedurally generated weapons and a crafting system. Instead I am just going to individually draw and author five named weapons for each class type, depending on the desired play style. The specific names will be easier to translate, rather than procedurally generated ones with names like: "Cruel Swift Dagger of Burning Flames". The grammar would not hold.
Upgrades for Skills and Equipment
I almost always use a five-rank upgrade system in my games. Instead I may extend to ten, requiring rare and limited reagents past rank five. Otherwise there is too much incentive to just dump everything into one specific upgrade that ends up skewing the difficulty curve too much.