BrainPOP has been known and loved by teachers and students since the early days of the WWW. It hosts some great 
resources including this educational games portal.
There are a couple of ways in which teachers and students could use these resources. They could let their students play them BUT looking to stimulate higher order thinking and getting kids to create and collaborate they could be used as models for students designing and making their own games.
This food chain example could be made as a board game or designed using one of these tools .
