My and my husband put a DVD on on Sun morning and then sneak back to bed for a couple of hours. I don't think full-on playing from 8 am is required.
And as for 'Daddy's ignoring me', I find this an odd thing to say for a child and wonder if those who said he may have overheard you saying this are correct. If my child said it, as they sometimes do say negative things about us, I would point out that Daddy hadn't been ignoring you and all the things they had done together. It sounds very manipulative for a child to say 'Daddy doesn't care as he doesn't comfort me when I'm hurt' and I can only think he wants you to hear this. I would personally nip it in the bud rather than encourage a 'me and you against nasty old Daddy' mentality.
If your husband is with you all weekend, doing family activities, and is even reading the paper at home but just not wanting to play, then he's more hand-on than many parents, and if there's a continuing issue between him and your son, then you need to think how you can enable them to be closer, not drive a wedge in there by painting Daddy as unfeeling and uncaring.
As for skinned knees, my husband never picked ours up when they fell over, he made them get up afterwards, and only then come for a cuddle. I thought this barbaric, but they are tought little girls and adore their Daddy, so sometimes mums don't always know best.