Plain gameplay involves choosing a hero and timing attacks. i press spacebar to hit a bubble that moves to the center.
Step watch the bubble move from left to center, and press spacebar at the right moment.
The main control is pressing the spacebar at the precise moment. The features include hero selection and a timing based bubble movement.
Most important is timing the spacebar press when the bubble reaches the center. This mechanic lets you attack enemies and stop them from overrunning you.
Q: What are the controls? A: Press the spacebar at the precise moment.
Q: What is the objective? A: Attack enemies that appear to stop being overrun.
Q: What is one stated feature? A: Hero selection with unique abilities.
Q: What is the main mechanic? A: Timing a spacebar press to hit a moving bubble.