Update 0.23.0

Horde Mode

1. map "Horde3" is added.

Weapons

1. changed the attack power of heavy cannon from 70 to 105. 2.
2. adjusted weapon sprites

Graphics

1. modified the night sky horizon to be brighter
2. added stars in the night sky. 3. restored CheckerBoardRendering.
3. modified the restoration algorithm of CheckerBoardRendering to improve performance.

Settings

1. Pixelized Lighting has been removed.