As you seemed to enjoy the Connect 3 (negative numbers) games today so much, here are the links to the NRICH site if you want to play the computer at home. (You can also choose to play a friend using the computer game on screen by selecting the play with a friend option at the bottom of the page (drop-down menu).
First connect 3 game with two ordinary (1-6) dice (instructions to play are here)
Connect 3 game with negative number dice (one with -1, -2, -3, 4, 5, 6 and the other with 1, 2, 3, -4, -5, -6) (instructions to play are here)
Have fun!