On the title screen, when Dizzy rubs his eyes, double click on him with the left mouse button.
He should collapse.
Then, double click on the log furthest to the right on the bridge Denzil is standing on.
Then, when Denzil is in the water, double click on him.
The "thing" to far right will fall off screen, causing the other "thing" to attack Dizzy.
Dizzy will stand up and run off screen.
When he is off screen, you can start the game with unlimited lives.
Simple, eh?