Thanks! =) What wave did you get to? I was a little late at updating the description. There are 8 waves and 7 germ types

@smithne You can use the '0' key to go back to the main menu and reselect the game mode. @Kartoffelbrot That is a good idea, but may not work well with the game modes, for instance: * In "Resourceful Rail", the train would get entirely too slow as the train grew, making the user have to wait a while before the train got to the resource deposits. * In "Running Ahead", multiple trains can travel on one route at a time and need not catch up to another. The other two modes allow the user to start and stop the trains, so I don't see the benefit.