Add Tails Player 2

[overbound]

There is Tails following Sonic code that can be backported to Sonic Time Twisted. This will allow for a 1.5 player mode like the classic Sonic games. Adding the ability to play 2 players in levels will break several things in the game. Specifically anything that is referencing the player one instance exclusively (example: player[0] instead of objPlayer). The second player will need to be tested game wide to look for bugs. An option to do a 2 player game must be added to the save screen too.

[AlexKhayrullin]

Even referencing objPlayer is troublesome, since if you reference a non-unique object in GameMaker Studio by its object name, the game will crash.