I did add one new thing to the game which I will quote here:
This new game mode is called “Endless Mode.” It is similar to the other main modes in the game, except this one features no levels and a never-ending supply of enemy ships. With no levels, each enemy ship is just slightly stronger than the one before it. This also means that each enemy, when destroyed, will reward a slightly higher score and money amount. With no break in-between levels, since there are none now, as well as no bonuses, you will have to stay on your toes after each enemy ship is destroyed. With the slight change to gameplay, you will need to think of new clever ways to stay alive.