All done! Finished the final two achievements (replay all the levels in Quick Play, and the quite difficult Complete Hangar 51 In Under 5 Minutes). The Hangar 51 one took 6 or 7 attempts, but finally I managed to do it in 4:46 having fluked three hits on the end of level boss. Phew!
That means I’ve 100%ed it, 1000/1000ed it, and seen and done everything the game has to offer. Hurrah!