School project. My game worked fine, then all of a sudden nothing works :/?!?!?!

So, yesterday me and a couple of friends sat for hours to complete the “game”. All of a sudden my game stopped working and it just shows up like in the video when I press “play”…
I honestly don’t understand what is going on…
The game is a sidescroller. where u fly a ship to catch balls and dodge obstacles.
Can someone help me understand what’s wrong?
(Like I said, it worked before then just stopped working…)

Are you sure that you want to “Simulate” the game and not “Play” it? Click on the arrow on the right side and click on the Play button (the first one). See screenshot.