Puzzle Generation in RGB & A Tale of Rapid Prototyping

Computer generated puzzles are usually no fun & RGB presents no exception to this rule.

The motivation for the basic gameplay mechanic of RGB came from another game I'm working on (more on that one later) that has a "crumbling floor" tile; you know, you can only walk over the tile once before it crumbles away & becomes impassable, forcing you to carefully choose your route. WHAT IF THAT WAS THE ENTIRE GAME, I thought to myself, IT WILL BE SO EASY TO PROGRAM DUDE JUST DO IT. So I did.

It was no fun.

A few iterations on that idea brought me to RGB but without the restriction on how many times you could visit each tile; spaces never became impassable. This was a mistake, I don't know what I was thinking. Anyway, I still didn't love it & didn't care enough about the game to lovingly handcraft puzzles so I just had each game start with a random board.

That didn't work.

Sometimes interesting boards would be generated but it turned out that many truly random boards are simply unsolvable. This is probably easy to prove mathematically but it was easier to just try it & see it fail. So, instead, I had the computer start with a board of a solid color & play the game backwards in order to generate the boards.

The puzzles were terrible.

Because by "play the game backwards" I mean "randomly move around & change the tile colors." I had the computer make a certain number of moves & reaching that number was the end condition for completing the board. What often happened is that I would end up with a green board with like 2 red tiles in the corner. So I had the computer look at the surrounding spaces before making each move & made it more likely to choose the least visited surrounding tiles. After completing the puzzle it counts how many spaces there are of each color & if there's too much of an imbalance it just starts over. This is a terrible, terrible algorithm but who cares, at least it worked. Sort of.

Every puzzle was way too easy.

So I finally introduced the tile counting mechanic so that you could only visit each tile 3 times. This required rewriting the puzzle generator to ensure that every puzzle was solvable but it finally made RGB feel like a puzzle game.

It's still not a great puzzle game.

The End.