"To spoil the experience" means to ruin or diminish the enjoyment or satisfaction that someone would have otherwise had from a particular activity or event. Full definition
They instead pointed to their open letter released earlier this month, in which they ask fans to not spoil the experience for those who haven't seen the film. (cbr.com)
I could not get enough of his remarks, and while I could quote a few of my favorites here, I wouldn't want to spoil the experience of hearing them for yourself. (pressthebuttons.com)
I really didn't see anything horribly wrong with the graphics or anything technical that can spoil the experience otherwise. (metacritic.com)