Hype Backlash: Shiki to some. His build up was good what with showcasing his past and motives and coming off as a interesting threat. But come the movie, his character seemed rather underplayed, especially when it came to the fights with the crew since they're so brief. Most usually cite the main problem is that he's always in the air for the majority of their conflicts and never really bothers to try to fight them head on (save for a brief mid-air battle that only last a few minutes). Instead just using his powers to try and swamp them with whatever element is on hand (rocks, snow, water, etc), ran the first chance he got when Luffy confronted him a second time and floating there like a moron as Luffy brought his final attack down on him. Considering that he had fought Gold Roger, Garp and Sengoku in the past, many were disappointed that he was just defeated by his own arrogance rather than Luffy managing to overcome his powers.
Praising Shows You Don't Watch: The One Piece wiki made a poll for the best OP movie, and Strong World won by a landslide. Fair enough. The problem is, the poll was created before anyone had subbed the movie. Oda's involvement and its canon status automatically made it the best One Piece movie, regardless of how the film actually turned out. Granted, some fans might have seen and enjoyed the movie before it was actually subbed, but this doesn't invalidate the trope.