Sherston Software has released updated versions of 'Mission:Control' and 'Crystal Rain Forest' CD-Roms. The first (pound;44.95) challenges children to save the planet Oglo from destruction using various aspects of control technology. The second (pound;59.95), using maths and logo software, features new graphics, animation and sound effects. PC and Mac. Contact Sherston Software Limited on 01666 843200. Website: www.sherston.co.ukwww.sherston.com.