Here come the traumatic memories of doing If/Then/Goto on TI-Basic, not understanding the Else or End tokens at all. Turns out each If/Then opens a new stack frame, and because I was never closing them with the corresponding tokens, memory slowly filled while the program ran. You could therefore get a high score of exactly 203 on my PONG clone before it crashed.

Good times! But seriously, take a few minutes to learn your tools properly if you use them more than once, it'll make things so much easier. :)