I get it now. So if there's a substring "TOUR", I can click on "T" and "R" to spin it; then it becomes "RUOT". After that I am not allowed to click on "R" and "T" to spin it again, because "ruot" is not a word. But i can click on "T" and later "R" to spin it in reverse - and then it does become "TOUR" again.

It took me a while to get it - extra instructions would be helpful.

You may want to show a popup message explaining that first time it refuses to spin. I tried playing, it kept blinking red, so I just gave up. If it weren't for the above comment, I would've never realized what was happening.

I'm trying to spin CAT as in the example. I press C, A and then it just blinks red before I get to T. I don't get how to play this.

If updating, remove any reference to Rubix Cube since it doesn't "spin" a row, that reference is adding more confusion about how it works than it clarifies.

Other words better than spin: reverse, mirror, or flip. Word reverser, word flipper.

Arguably more a mix of wordle and boggle or scrabble than Rubix.