I've just discovered a really useful and fun web site that has lots of free games to help kids practise their mouse skills  - basic eye-hand coordination, and timing skills. It is not for 'first beginner level' users  but great for kids who are mastering the basics of moving and clicking. There are very simple games to enjoy that are just about cursor control and clicking (simple painting, popping balloons etc.), but the site also offers quite testing games bringing in very simple off-screen scrolling, challenges of speed /reaction time, and click and drag skills, and cognitive skills like planning, basic spatial reasoning, judging height and distance, estimating trajectory etc., as well as consolidating basic counting andshape/colour matching.

A comprehensive free and fun playground and training ground for the mini gameplayer, in fact. (doesn't work on iPads, though)