This app was mentioned in 13 comments, with an average of 1.46 upvotes
I would look at Zoombinis (https://play.google.com/store/apps/details?id=edu.terc.zoombinis&hl=en_US&gl=US) it a game designed by some really good learning researchers. It is fun but also teaches kids critical problem solving skills. Pretty sure it doesn't need the internet to run.
I loved zoombinis! They actually recently did a Kickstarter and you can get the remake on the play store here
For those of you with Android phones (preferably with a big screen), here you go!
https://play.google.com/store/apps/details?id=edu.terc.zoombinis
Essentially everyone I know who is in STEM fields in their early 30s played Gizmos and Gadgets! as a child. https://en.wikipedia.org/wiki/Gizmos_%26_Gadgets!
Also, The Logical Journey of the Zoombinis is another classic that I've heard held up as an example of a successful educational game. https://play.google.com/store/apps/details?id=edu.terc.zoombinis&hl=en
Logical Journey of the Zoombinis: https://play.google.com/store/apps/details?id=edu.terc.zoombinis&hl=en
Hey guess what, if you have android you can get it in the playstore