Brick Complex is a 3D puzzle and building game. You use simple operations to combine basic shapes into increasingly complex constructs. You solve structural challenges, from quite easy to difficult.
There is also a sandbox mode where you can hone your skills and build to your heart's content. You can then share your creations and even incorporate and build on those of others.
Brick Complex is a challenging and novel puzzle experience that will give your three-dimensional problem solving a good workout. Give it a try. It's free!