"Hunter." The play area is a big part of the neighborhood. The details were a little variable depending on different experiments or how many people were playing, but one canonical version is three hunters with walkie-talkies, trying to find two people without walkie-talkies, with a time limit. No other rules aside from don't piss off any neighbor inside their house overly badly.

A good solo game for long car trips was looking out the window riding an imaginary motorcycle. You can go up on power lines if there's a slanted wire you could ride up, you can move left or right, but if you box yourself into a place where you'll hit a vertical wall no matter what you do, you crash.

Various hallucinogenic DND-but-not-really variants played with no sourcebooks, and a piece of paper with a grid with numbers that you flick your pencil eraser at with your eyes closed to "roll dice."