I have some suggestions for the game:
1-Cooperative multiplayer mode:
* In the dungeon are found some monsters, there could be a cooperative mode where players help each other in a sort of expedition to defeat “greatest” monsters, like a dragon or a kraken.
* Would not it be interesting if there was a system of duels between players? Without troops, only each player with his skills (read my suggestion 3), could work with shifts or be a battle in a field with obstacles.
3-Advanced equipment system.
* Imagine able to increase the skills of your hero? Could be gained 1 point to increase his powers by level, and there could be classes of heroes, let your hero as an archer or as a mage, the troops could also be equipped with weapons and armor different to change your skills without leaving your base, example: the pyromancer use a clothing / specific weapon does he use volcanic rocks that cause some different effect than standard attack.
4-Best in Animations spells.
* The blizzard could be with his hero lifted his weapon above his head and the floor around his feet would snow.
Those are my suggestions, what is your opinion of them?