I had a lot of fun playing an Android game where you find words in a random grid of letters (like Boggle). Challenge for me was to find the longest word... and seeing which I missed was a way to learn new words.

I've iterated on the concept, and made a game you can play in the browser, Gridogram: instead of being random, for each day a grid of letters is created from a quote that relates to the day.

For example, here's a grid where you can find the Y Combinator motto [1]:

  E G I W
  L H N A
  P T M K
  S O E P

Finding words: connect horizontally, vertically or diagonally adjacent letters, without using the same letter twice.

On the development side, an interesting challenge is figuring out the smallest grid a quote will fit in. I create an undirected graph with the letters in the quote, count the nodes, ensure the number of edges each node has can work in a grid... but have found that such a graph still won't necessarily map to a grid, so next step is to learn more about the subgraph isomorphism problem.

Grids vary between 3x3 and 5x5 (computationally, 5x5 can take a lot of time to generate). Some are quick to play, with players solving them in tens of seconds, some are very difficult indeed.

Would love to hear your thoughts on the game.

[1] "Make something people want"