Version 0.1.3 RELEASED - Shield powerup, Air Dash tuning, and more

Release notes:

• Powerup - Shield (NEW): Grabbing this powerup will give you an instant 10-second immunity from all projectile attacks.

• Powerup - Health: Now divides your knockback damage in half. (Previously subtracted your knockback by a flat rate of 60%.)

• Air dash: Changed buttons to activate "air dash" in twinstick controls. Now activated by single-tapping the top bumpers. Double-tapping the left joystick is still active, and air dash for bumper controls are unchanged. (EDIT: It appears that the change to the twinstick air dash did cause some problems for the bumper controls. This will be fixed in the next update.)

• Sound effects: Added sound effects to Main Menu and certain in-game events (such as the air dash), increased volume of water rising audio.

• Controls: Can now end match and quit game with keyboard controls.

• Bug Fix: Removed a situation in which a player's own projectiles could cause damage.

A big thanks to Vaelsh for giving us the feedback about the air dash being controlled by a controller's bumper buttons. We agree... it is a better place for them.