OK, so I was mashing buttons trying to make the tank shoot or something and then the first tank exploded when I hit shift and my score went up.

"Oh", I thought, "it's a game about killing tanks that you control! Ha ha!"

Then the shift key wasn't working anymore, so I drove around some more and mashed some more keys and my tank exploded at the same time I hit the space bar.

"Oh nice, it's about blindly triggering suicide sequences that are different per-tank! I wonder if they get more elaborate?"

Then I got to the right side of the screen