When you use a seed, you always spawn the same map, but your spawn location may be in another location, though close to the normal starting point set (approx 255 blocks) you may have to walk around a bit to find the hills. When I first spawned on it I was on a beach and had to do a small walk to get to the hills.
That pumpkin is fun, see there's two coal below it? It's like a rocket!
If you look at the pumpcan (with the waterfal behind you) look to your right and walk, theres a small hole with some iron, dig around there and you get into a cave system with a lot of goodies in it.