Solving the Rubik’s cube
You either get into speedcubing and get high end cubes to improve your performance, at least of the official categories and a couple must haves like the Mirror cube.
And / Or
You start collecting cubes and puzzles of all kinds and shapes (yes, even non-cubical :o). You start to acquire custom cubes built by hand by artesians or niche brands.
For the love of what’s good in this world, stick to that one budget MJC set of competitive cubes until you are actually 10 or 20 seconds behind the world record
To be honest you can get Cave Story for free already since it’s open source and in many distro repos. Also I think the publishers kinda ripped off the original creator so the guy who actually put the work making this masterpiece isn’t getting anything