Fix input polling

The way the inputs were polled and processed prevented simultaneous
inputs from all players and would interrupt one player's inputs when
another input started. This should be fixed now.

1.0.0

Most issues have been fixed. Some things left to address are:

• The color for the ground has a blue tone because the sampling of the texture is bugged
• The audio for the mouse cursor is not playing in the same way as in the original
• There is no audio panning or pitch shifting

Initial release

The basic gameplay works but there are still some issues and some cleanup is required.