Version 0.13

Bugfixes:

- Hero collision box getting stuck on corners

- Modified the player's affect on the built walls

- Modified the player to collide with the boundary walls

- General performance improvements

Feature changes:

- Added ability to change build size from 1x1 up to 5x5

- Added a new tower unlock after the 5th wave

- Moved the hero spawn point

- Updated to new input system

- Changed the player sprite

- Tweaked the building mechanics to be more fluid and less performance impacting

- Changed the hero sprite

- Updated tutorial text to reflect changes