It is substantially smaller than the Wii U version, as I completed the story (without much in the way of wandering round) with just over 7 hours on the clock. There’s clearly a lot left to do, but I’m expecting around 25 hours to 100% it.
It’s a great game. It really is. The only reason it isn’t fantastic is that the Wii U version exists. Still, lots of fun and I’m going for the 100%. Just a shame the ending didn’t tie in with the “flashbacked” ending in the Wii U game. Bit odd that.