There have been big changes through this 2.0 update.
By merging poison bottles, you can get various chests.
You can get various pets and items from chests.
Inventory is erased.
The way to obtain, use, and level up pets and items has changed.
The UI for heroes, inventory, research, etc. has all been changed.
Quests and Dungeons have been added.
Achievements have been added.
A new pet has been added.
Some pets' skills have changed.
Hero skills have changed.
All balance have been changed.