Tesserian

Did you ever wonder why we live in a 3-dimensional world and how it would be to live with one more dimension? Tesserian guides you in exploring 4D space with an intuitive introduction, a tutorial and over 100 puzzles to solve.

But beware this is not for the faint hearted, some real challenges are ahead.

PS: If you want a preview in 3d go to https://eretrandre.org/tesserian/3d/