score:1
The problem is that by boarding the plane, legally speaking, your flight started.
It is likely that you will arrive late. So possibly you will qualify for some amenities at your destination.
NB: There are reports that some airlines might by full purpose have passengers board knowing well that the flight will depart at all or not within a reasonable amount of time, so they will have to unboard passengers again without ever leaving. But as this breaks the 2 hours / three hours rule, no compensation, at least not in terms of meals and the like.