I don't know if this qualifies as hack, but as a kid I was pretty proud about changing the code of qbasic's nibble.bas to get infinite lives. If I remember corr

I don't know if this qualifies as hack, but as a kid I was pretty proud about changing the code of qbasic's nibble.bas to get infinite lives. If I remember correctly it lead to some further experiments (snake's length, level editing) and eventually I managed to break it completely.