Haven't read the whole thread but these are my thoughts:
I used own a house (not in Grantham) which would had a very similar layout, so that felt familiar to me, even though this one has been altered in ways that mine wasn't.
Ignoring decor, which most people seem to want to change straight away anyway:
It's on what looks like quite a busy road. I can see a bus going past during the tour video! Is parking outside possible? It says you have a double garage - where? What's the access between garage and house/garden?
The garden is quite frankly a mess. Those unkempt fences either side suggest to me that neither you nor your neighbours have done any garden upkeep for a while. It's a 4 bedroom house, you have children's bedrooms - it doesn't look like a garden for children. You need to cut stuff back to open it up. If you can do something to smarten up the boundaries, so much the better. And the area which is enclosed between your offshot and the neighbour's is just depressing (visible on photos of previous listing years ago).
Like everyone else, I think the kitchen looks weird. And again - 4 bedrooms - children - where is the family going to eat? The eating area at the end of the island doesn't look big enough. If it is, then maybe you need to dress that bit of "table" to show it.
Where's the storage? I'm guessing that the cellar has been converted, as has the attic, so you've lost those storage areas. My old house had understairs cupboards too. I can't see them on these pictures. 4 beds, children - you need storage.
Those stairs down from the attic room look pretty steep - are they compatible with regulations?
I really like the bathroom. But where's the pictures of the ensuite? I see a closed door which obviously leads to it but you need to show it.
It was built in 1904 (according to the stone on your neighbours) and it has "period sash windows". What are your bills like? That loft conversion was clearly done a while back -- insulation? Could be baking in Summer and freezing in winter. What's the damp proofing/tanking like in the cellar?
That's before all the other stuff -- price - local schools - amenities etc. Sorry!