how small are we talking? I think as mentioned Hammamet may be your bet choice of options, as in yassmine there is cathidge land, and ice skating rink, plus your not far from Fruguia, though not been myself.
Also in Yassmine an English expat has opened an inflatable park
http://www.bouncytune.com/index.php this is in french or you can see this onhttp://www.nomarmiteintunisia.co.uk/wehaveabusinessouthere.htm