You can defeat enemies to unlock items and characters in the story mode. Most of the characters can be unlocked by completing achievements. You don't need to purchase certain NanoMonsters to unlock them. But we will be very grateful if you support our game.
It is important to know that aiming the target using touchscreen is extremely hard. Therefore, we created "Moving Attack" system. You can move a NanoMonster by touching left-half of the screen and long-pressing right-half of the screen to aim at the specific target. The trick would be very useful when you shoot at target enemies.
How to pause the game?
It is actually a hidden function. If you can pause the game successfully, you can unlock an achievement.
Hint: Use 2 fingers simultaneously.