Defeat all of the monsters and level up all three of the heroes to level five.
They each need a different number of experience points to level up: blue need 33, yellow needs 55, and red needs 77.
Slide the heroes the move them on top of the enemy to attack.
It's also possible to cancel a move by touching the enemy under attack.
Let the battle commence!
The answer is as follows.
blue=11, 49
yellow=2, 14, 26, 58
red=4, 18, 29, 89