Building a game out of spite

So, I just built a (very simple) web game: Number Sum . The game is a brief number guessing game, in the same vein as Sudoku and others. You have to complete a partially-filled grid with number guesses to ensure that certain conditions are met, namely that all columns and rows sum to the respective hints given on the grid. It took me about two hours to build (plus a few weeks of wanting to build…