Science:
Food Chain Game- http://www.sheppardsoftware.com/content/animals/kidscorner/games/foodchaingame.htm
Fun Food- http://www.harcourtschool.com/activity/food/food_menu.html
Food Chain Game- http://www.bbc.co.uk/bitesize/ks2/science/living_things/food_chains/play/
Life Cycle Game- http://www.sheppardsoftware.com/scienceforkids/life_cycle/games.htm
Producers, Consumers, Decomposers- http://www.sheppardsoftware.com/content/animals/kidscorner/games/producersconsumersgame.htm
Water Cycle Game- http://www.epa.gov/safewater/kids/flash/flash_watercycle.html