Don't know much about Scratch but both DS10 and DD10 are into Minecraft although in different ways unless they are playing each other. DD is more into designing (skins, etc.) and likes it when strangers download her designs. DS is more into strategies (hence, all those youtube videos) and battles. I had to pay twice for the PC version so they would each have an account. The Pocket Edition for Kindle is nice as well and I only had to pay once since their Kindles are on the same account so all the software in the library can be shared.
I am very comfortable with un-monitored access to Minecraft at DS/DD's age and a couple of years younger but I would have been hesitant about introducing it to a four-year-old due to addictiveness/self-control issues.
Oh crap... my 4 1/2 year old has been playing minecraft on his computer for about a year now. I have worried that it isn't good for him. However, he does not like to play alone too much. He does seem amazing at it - my older DS keeps admiring younger Ds's "mincraft giftedness." LOL I have to admit this little guy builds spectacular things on it but I have no computer interest or abilities and no experience (or interest in) minecraft so I don't really appreciate his creations or apparent abilities. Incidentally, this kid is really good at all kinds of puzzles (well above his age-level) tangrams, block puzzles, etc. I suspect he is very visio-spatial. But I do hope it's not harming harming him somehow!
