Tic-tac-toe is a simple game (usually played with pencil and paper) that can be enjoyed by kids as young as three. What I find most fascinating about these online tic-tac-toe games, is their variety. The many creative twists that can be put on such a simple game are amazing.
When you add another dimension to the usual three-by-three two-dimensional board, tic-tac-toe is no longer trivial, and it may take a few games until you can easily visualize the three boards stacked on top of each other. One interesting twist to the game play is that although each "three in a row" earns you a point, the game is not over until all the cells are filled. At Arcade Town, the human player (that's you) always starts, and always plays as X.
This game is unique because it lets you customize the dimensions of your board. You can choose from the traditional three-by-three, or any size up to seven-by-seven. Of course, increasing the size of the board, increases the difficulty of the game. Other choices include who goes first, and whether you want to be X or O. And for those interested in programming, the author provides a behind-the-scenes look at the game's decision-making logic.
This clever game, disguised as tic-tac-toe, is actually a math drill. To place your X in a square, you must solve an equation. Choose your math level from Easy to Super Brain. Then select your operations, which range from addition and subtraction, to cubes and square roots. If you find yourself in a math level too high or too low for you, instead of returning to the main menu (by clicking Start Over) try the Easier or Harder buttons.
"A habitat is a special home where animals find food and shelter. Try this fun tic-tac-toe game to discover some of the creatures that make their home in the kelp forest or the deep sea." Instead of boring Xs and Os, you can play tic-tac-toe as a purple ochre starfish or cock-eyed squid. After playing, move your mouse over the creatures to learn more about them and their habitat. The Play Again and Start Over buttons are hiding (in plain sight) in the upper-right hand corner.