Doggy is simple to control: up, down and jump are all that is required. Avoid the walls and pits and other such obstacles; collect bones to top up your energy bar; prevent your energy bar from hitting zero. There are also confrontations with other dogs, which gives you a choice: you can either avoid the other dogs (by jumping over them), or you can fight them. Fighting them initiates a chance roll (and a cloud of dust) and if you lose the roll you lose a life. Win, and you get a thousand points. While fighting is a good way to gather points it is also highly risky and will always lose you a good chunk of energy, so should not be attempted when your energy bar is already low.
Doggy is fun to play for a while, but you have to get into the rhythm of it. And, of course, the levels become much faster and more challenging the deeper you get into it. Definitely an Oric classic (in spite of the horrible colour clash).
More: Doggy at Oric.org