Truth be told, I couldn't think of a sensible reason for needing to knock over giant pins. There were certainly options, such as timed pressure sensitive plates that had to be triggered together quickly to make something happen, or the pins themselves destroying the wall behind them, but there was nothing I could think of that felt more satisfactory than the whole thing being entirely unnecessary.
To be fair, however, it would have been more difficult to find that opening with the pins in place.
It could also be claimed, were this story attempting to be taken the least bit seriously, that the bowling "puzzle" could have been a trap, and that any not as absurdly sturdy as Nanase would not have come out of it in any shape to continue.
As this is a story in which nothing should be taken the least bit seriously, however, it can be assumed that Sarah could have safely had a go without risk of serious injury. That leaves the question of how they would go about resetting the pins, but as this takes inspiration from video games, the answer is doubtlessly to exit the room, and then reenter.