Almost completed this game. Only about 20% of the coins are left to get and the only trophies I don't have are two of the Golds and the Platinum (not gonna worry about maxing everyone's levels). Just gave challenge mode a try and shit is that Marineford level hard. I was doing good until the three admirals showed up (Kizaru is the most irritating boss in the whole game). Managed to beat the archipelago level though.
Need to play online more to get friend coins.
Overall this is a great game. Will definitely buy it again if it's brought stateside