Just come across these amazing light up advent calendars! They do Star Wars and Trolls at Tesco. Each has 25 doors with chocolates behind them and they light up when you press them. They are kinnerton chocolate so totally nut free and no artifical flavors or additives.
Star wars and Trolls ones are £3 each at Tesco and they do Star wars, Trolls and a finding Dory at Asda for £3.50 each. They also seem to do a Star wars BB-8 light up one in Marks and Spencers but I can't find any links or details so must be instore only
Edit - The BB-8 ones are in Marks and Spencer in store only £5 each or buy one get 2nd half price making £7.50 for 2 or £3.75 each - picture in comments
I will post a video and links in comments.