Thanks for the feedbacks.
I collect puzzles to both watch and play.
That's why I don't bother trying to collect every puzzle in the world.
These puzzles I collected are very aesthetically pleasing, and a ton of fun to solve.
how hard are the Hexaminx and 2x2 Circle cube to solve?
Even though Hexaminx is basically just megaminx, it is very confusing to solve, since it is hard to determine whether I turned a face correctly. (When scrambled, it becomes a HUGE MESS.)
Ironically, the mechanism of Hexaminx itself is slightly easier than megaminx, since some edge orientation can be ignored.
Still, solving this beast is very hard, taking hours of effort. I haven't broken my best record of 1 hour and 56 minutes.
2x2x2 Circle Cube is not that hard, if you come up with the right solution.
My current solution uses only standard 2x2x2 cube solution and one extra algorithm, and it works perfectly.
Furthermore, it can be solved fairly quickly. My best record is about 100 seconds.