Tic Tac Toe for MS Excel by Steve W (zip download).
If you plan to do an advergame for your next client, consider alternatives to the ubiquitous Flash. A refreshingly underutilized advergaming platform is, surprise, MS Excel, the very spreadsheet program that eats away your best years. For inspiration, look at these sites: MrExcel.com (Mastermind, Snake, Hangman, Tic Tac Toe), CPearson.com (Minesweeper variation), and a page on Geocities (Bejeweled variation, a pool game). And finally there's an Excel plug-in that helps you with all your Sudoku needs (and a few more).
Of course, you can also draw in Excel.
