New systems/services like:
- main menu
- title screen
- configurable controls for keyboard and gamepad
We also adopted pygame-ce as the game library in lieu of regular pygame.
Python 3.7 or above is now required to play the game.
We also added the needed backend to support input playing/recording. Such services are mostly functional. They were tested and were working fine before, but now they need a few small changes to take into account recent changes/additions related to the usage of configurable controls for keyboard and gamepad.