I didn't find the 7 levels to be too short of an experience, but I obsessively searched everywhere in each chamber to find every gem on my first completion for all of them. So that's awesome that the devs will be adding more content.
And wouldn't ya know the only GC sync issue I get is on the final chamber. I was able to re-sync the complete chamber 7 achievement by passing it again, but unfortunately since I already got all 6 gems, the gems achievement didn't unlock. Could the gems be made to re-sync upon chamber completion like the other achievement in a future update?