It’s an example of what the average behaviour will be.
(Average behaviour, not mathematical average.)
I’ve seen it happen in development of at least two games,
so it’s not so rare as to be irrelevant.
There are people here who push the boundaries of the RAM in the pursuit of good quality games,
so such occurances are eventually inevitable.
‘Simple arcade games’ aren’t the games that are going to be needing to check their stack usage.
Though I’d say there’s quite a lot of games for the Arduboy that are more than just ‘simple arcade games’.
Even games that seem like simple arcade games can be more complex than they appear, or can eat more RAM than expected.
But the alternatives aren’t necessarily the same.
Branches can be drastically different, especially when there are state machines within state machines, or complex calculations.
One branch could overflow purely because it has a few more variables than another.
If a significant amount of RAM is in use then having 7 stack frames instead of 6 can be the difference between normal execution and stack overflow.
That difference could be something as simple as a previously inlined function no longer being inlined because it’s hit the usage threshold.
I.e. the usage can change as the program evolves.
But at any rate, this is getting off topic.
The original point was that most people tend not to write games that make heavy use of RAM purely because there isn’t much RAM to work with.