Magic:
- Make spell books different from one another.
- Magic is supposed to be something rare that can destroy of heal the world. Make magic users something to be feared or at least respected compared to other units that can be present at the current game phase.
Heroes:
- Traits, advantages, bonuses. Anything that will make heroes more than just a unit that can buy items.
- More than just a few ability points each level. Maybe more/stronger traits?
UI:
- Well... a lot of changes...
General:
- Tutorial
Many other changes are needed, but I think these are the more urgent ones.