What precisely are they going to spoil, or indeed cause to possibly percolate up into general conversation where you might not avoid it unlike actively having to watch a video, which will so impact your enjoyment of a Mario game? You tell me there is a level in mario sunshine where you ride a roller coaster shooting a giant boss and I will look forward to it, tell me Aeris dies mid game in Final Fantasy 7* and you will have a) made me realise why it follows the patterns of so many similar games and gives you the ultimate weapons and abilities so far in advance of everybody else and b) possibly robbed a later scene of some poignancy. Barring certain kinds of run and music hack then the fun of mario is in the doing for near everybody I ever met, not the watching which is in contrast to quite a few other games.
*normally I don't feel the need to justify things but there's a limit on these things and 20 years of a fairly well known event, one satirised countless times since, gets there for me. If I have however ruined the upcoming remake for you then good.