So far I've completed every quest except for the "find all the statues" and the last 2 score quests. The problem is that for whatever reason, I can only stand playing for a little over an hour before getting really motion sick, and the score tally resets each time you start a new session. I've only ever gotten about 2/3 to the normal score goal, so the hard seems unfathomable.

Any pro-goat-tips?

Between the house and the gas station I've wracked up a million in a run.

Ahh, I hadn't been using lick or kick all that much. It seems obvious in hindsight, but I would imagine mixing the tricks up a bit probably keeps the combo going longer than just headbutting over and over, huh? That should be useful, thanks.

A good way I did it was through the Low Gravity Testing Center. Maybe it got changed, not 100% but I managed to get the high scores just by going on the fans there and constantly spinning/flipping.

I got into the house and wrecked shop, and stuff kinda happened? It just kinda happened...... GOATS

It turns out there IS a quick and easy way to get a crapton of points. As Angel Goat (jumps higher, hold R in the air to fall very slowly), head over to a trampoline. Jump a few times to get some height, then hold R at the peak of your jump and start spinning. You'll spin quickly enough and fall slowly enough to make like 40+ full rotations. You may need to land on the trampoline to avoid ragdolling when you land (although I think the Angel Goat power protects you from that).

Using that trick, I went from 0 points to well above the Hard score threshold with a single jump.

*edit: I recorded and uploaded a video of this trick