This raises a very good question, if Linux is to become THE operating system of choice in the future, it must have all (and more) of the software support that Windows has. I personally am not familiar with any mainstream childrens games that are available for Linux. What I can suggest is for you to take a look at a program called Vmware. Vmware is an amazing program which lets you run other operating system in Linux, i.e. Windows. It does this by creating a virtual disk within Linux onto which you must install the OS which you wish to run. I've installed Windows98 in Vmware and had both internet connectivity as well as complete sound support. The downside of vmware is that on older machines it can be painfully slow. Unless your machine has 128mb of RAM and is at least a PII 350 I would avoid vmware. Vmware is available from
http://www.vmware.com and is free with a 30 day license. At the end of the 30 days you can just download another license for free =). Make sure you check out the screenshots on
http://www.vmware.com, it's pretty impressive.