About Tumblers

This game concept came to me when I was thinking about how a Rubiks Cube works and how I could make something along the same lines.
I'd like to give more insight into the creative process, but the truth is that the idea pretty much popped into my head in one go, with very few changes needed:
A puzzle made up of grid of tiles and a random set of buttons to manipulate it. I did consider having both colours and symbols, but decided against it.

The obvious way to generate a puzzle, would be to pick the set buttons to be given, then start from the end-state and scramble it with a series of button-presses.
And, yes, that worked. The back-end development for this puzzle was very straightforward compared to some of the other games
I decided that for simplicity, it would be easier for the end-state to be a grid filled with one colour. I think having any kind of target pattern would be a large jump in difficulty

A small mistake I caught early, was that the choice of buttons couldn't be absolutely random, as a random set may not contain any buttons that change colours. Seeing as the solution is all one colour, there needs to be a way to change some colours.
Another similar fix, was that the selection of shuffling moves couldn't be purely random either. When I had the shuffling script using completely random choice, I would occasionally get a "shuffled" grid that hadn't had any tiles changed from the original colour.
The final version would first ensure that it was able to change colours, secondly that the first shuffling move would be to do a colour change and thirdly that the final solution could not be solved by a trivial sequence of button-presses.

And that's about it. The rest of development was creating 3x3 and 5x5 versions and working out how much to shuffle for each difficulty level.
I hope you enjoy my strange creation.