Engineering+Games

It would be great to see more 3D spatial visualization and things that appeal to girls in particular.

Some do exist, but there is always room for more. These can be gender-neutral, just not a big turn-off for girls.

Some spatial awareness puzzles http://samgine.com/free/spatial-awareness-puzzles/

Lots of games here, some could be considered pre-engineering http://www.abcya.com/

Not sure that this is actually a "game" but coloring is big and these are great https://www.theguardian.com/science/alexs-adventures-in-numberland/2017/may/01/the-colour-of-numbers-visions-of-our-mathematical-universe

Girls often struggle in early engineering programs because they don't have as strong spatial visualization skills as boys with much lower GPAs. Some engineering schools are finding ways to address this based on work in Introduction to 3D Spatial Visualization: An Active Approach by Sheryl Sorby, Anne Frances Wysocki, Beverly J Baartmans Lots of good material. It would need to be adapted. https://www.alibris.com/Introduction-to-3D-Spatial-Visualization-An-Active-Approach-Sheryl-Sorby/book/7429748