I think they made a computer version of crash bandicoot but it would be very hard to find. You could maybe try Rayman. I know for sure that they plenty of those for computer. Its a lot like Crash bandicoot but in a low tech side scrolling way. The newer ones are from the 3rd person view just like crash. If you still have the game disc you download an emulator which lets you play PS, PS2, dreamcast, etc. games on your computer.
you can pick up some older sonic games pretty cheap that'll look fine and keep those 6 year old fingers busy............got a 3 yr old dotter myself so we're still pointing and clicking.
although this same 3 yr old just loves to help me with the xiii demo when mum's not lookin'
Doddsy lets be honest here you are a bit partial to a wee game of SONIC yourself big lad I can see you fighting over the controller and as for XIII a little birdie tells me your 3 year old can wip ya at it!!!