Local pvp version 0.5.0-alpha

This is the first official version of the little game:

• Godot v3.5.stable.official [991bb6ac7]
• Sound effects
• Main menu with fullscreen, brightness and reset score settings
• Life and energy HUD

The initial idea was to write something like archon from the Amiga in the past. There you had a phase where you had to shoot each other if you had to fight about a field on the board. What came out is a little different, though. It is still very little and you can play it "only" with two players and gamepad. But there are some mechanics that can make some fun already, I think.

The next step I wanted to check out is whether I can add remote play. Godot provides some good functionality for that.

Another idea was to add another game mode. Something like PvE. But this demands a lot more assets...