"We bought the set for our son's 6th bday and were wondering if he would be able to build it alone. I'd say he needed our help with the robot/ipad maybe 5% of the time. The set is very expensive, but as my son is more a builder and explorer than a child who actually PLAYS with lego (role play etc), this set is perfect for him; he spent already hours building and coding the robot. For his bdayhe also received several lego sets from his friends. They are all built, but just laying around after an hour of building. If you compare prices then i'd say they playtime-per-dollar is higher on the boost set than on the usual sets. Today, 12 days after receiving the gift/starting the ronot-build, he suggested we take the robot apart and built the next one. The cat. Taking the robot apart was a bit of work and I helped with that. Now he's quietly building the next challenge. Bliss! What I find a bit annoying about the set is this: 1. All the parts our now out of the numbered bags and thus it is harder to find pieces. DIY Solution: We have color sorted the pieces and placed them in large resealable bags so they can lay flat and show all the pieces of the color while the pieces are not laying around on the floor (we have a baby, too). 2. We will need to buy a resealable box to put the parts and the card board playmat, that comes with the set, in. This is not like usuallego and there are many very specific pieces. If these 800 pieces would be mixed with his normal lego (about 10 -15 sets + some classic brick boxes) he'd never be able to find the pieces back to build any of the Boost figures. Too bad the set box doesn't allow to be used long term - it being card board and non-resealable it doesn't lend itself well for storing. it seems one piece is missing (see-through 2 dot red brick) as it was not used for the robot, but it is also not in the left over bags. Will need to ask if it can be send still. 3. it needs 6 AAA batteries and as he, of course, codes and recodes the set and tries it all out, batteries die really fast.I am a bit surprised it didn't come with a rechargable battery (with the option to buy a spare one if you'd want). I hope this is something that will be available for purchse soon in a way that people who already own a set can use that option too. This especially in light of the fact that the set IS in fact expensive and I cannot simply buy an upgraded version. I hope extension boxes or App updates will come available. Ideally extension boxes that "grow" with the kids, so in two years from now he still will be challenged with building and coding these robots."