How would you distinguish between "at the game" and "in the game"? Just by context?
I'm interested to know that, too.
Why is "Canais i'n uchel ar y gêm rygbi"
yn - in, at
ar - on
However, the sentence "gwenais i ar Megan" = "I smiled at Megan".
So this is not a hard-and-fast equivalence.