A game

[PutraenusAlivius]

@Bridge
Yes, you do press down all the buttons simultaneously. Since there's a limit, you wouldn't get *that* many, not much, at least below 10.

@Chronofrog
You have to position all of your fingers in different keys, not just one key.

@Danny Boy
Make a sentence out of it. Just use your imagination.
LIKE:

"I went to hrkki (City) to buy u4oo9 (Item) at l8njakem9s (Something) yesterday."
Use your imagination!