Some days you're just looking for a competently-executed escapist popcorn flick. This isn't one. It makes no sense — merely moving from one CGI set piece to the next — and the dialogue is excruciatingly bad. Much of it is impossible to follow if you're not steeped in recent Marvel lore. This might be forgivable if the imagery was any chop.
On the plus side, with half an hour to go, director Sam Raimi went all Evil Dead silly with a zombie Benedict Cumberbatch. (There's also a Bruce Campbell cameo.) But we've seen all that before.
A. O. Scott: dutiful fan service. This multiverse is so much less witty and imaginative than Everything Everywhere All at Once's. The best bits are the 1980s Raimi bits. Elizabeth Olsen is scary because she is so sad. Wikipedia: 294.5M USD of hot mess.