I've just finally got round to watching this today. To be honest, I only watched it for some exaggerated mugging by Jim Carrey, and that's pretty much the only good thing about it. When the mask is on, the gloves come off, and Carrey lets rip so violently, it's hard not to laugh. Small moments like 'NO! It wasn't me! It was the one-armed man!' amuse, while the Mask's set pieces are bizarrely hilarious.
But (and this is a big one), whenever the Mask isn't on-screen, it is worryingly terrible. With some of the most soppy gangsters ever as the villains, and Cameron Diaz attempting to pull off pouting as acting, it verges on embarrassing, and not just that, but boring too.
The Mask is simply a showcase for Carrey's rubber face and some neat special effects, but other than that, it's as flat as Carrey when he becomes 'road-kill'.