There is not a time limit in the unregistered version as Catz has. Each Dogz develops its own unique personality as it grows and, like a real dog, the personality reflects how it is treated. There is a convenient, built in, screen-saver which also offers password protection. The only thing that your Dogz won't do is mess on your desktop. The program is well written and it won't interfere with any other program that you may have running at the same time.
Support is available via phone or e-mail.