If the plot hole(s) mean that the entire movie/game could have been resolved in 5 minutes if everyone hadn't been acting like an idiot, then yes, plot holes can ruin a movie.
Eagle Eye is my go to movie for this, but most people didn't see it so I'm both glad(that I'm the only one who wasted money on it) and sad(I can't use it as an effective example).
Interestingly, having a bunch of plot holes otherwise is not a deal-breaker but can affect my enjoyment of a game.
I recently replayed the COD:MW games. MW2 has a lot of loose ends and plot holes, but generally works because the overall theme of the Cycle of Revenge and the setpieces in general.
Unfortunately, MW3 was made by a completely different team who apparently didn't seem to get the whole "War is Bad" memo the previous games were operating off of. It also introduced a bunch more plot holes and contradicted at least one very important plot point from the previous game(The same Russian President who ordered the genocidal invasion of the US is suddenly all into a peace treaty, Makarov suddenly running the Russian army, Price hanging out with the Delta team despite being the 2nd most wanted man on earth), making a bunch of stuff make little sense. So yeah, a lot of the missions are fun to play but now feel like a series of barely connected scenarios then an actual plot.