1. More heros
2. Weapons!!!
3. More enemies and bosses.
4. in game quest menu (has info about the map and heros such as classifications as well as loot drops and percentages)
5. More waves
6. More area's
7. Mana potions (combat consumable)
8. The Upgrade center with those awsome helms (poisidens helm etc.) and have the other kinds of armors as well as weapons there.