I have found 349. World 1: 84 (68+16), world 2: 68 (33+35), world 3: 55 (22+33), world 4: 62 (38+24), world 5: 53 (41+12), plus 27 from masks.

However, that is not a round number, so I wonder if there's more. That stalagmite on the bottom-left of the third area of the cleansed world 1 looks very suspicious. Also, what does the number 275 correspond to? Having either more or less grins doesn't seem to affect anything.