Well I've been playing it all day lol. Just thought I'd give some info as I can't find much about it at all on the net.
It's obviously the same as the other gigas, but with Reptar.
For food he eats cars or ice cream stands/trucks (that's the treat option).
The game is you have to hit the helicopters (I think that's what they are) with his tail, they appear left and right so you press whichever direction button to make him hit them.
Sleep is obvious, then there's the tricks and treats bit. You can teach him to do 5 tricks: He dances in a top hat with a cane lol, breaks out some animals from their cages, Ice Skates (I think), Bashes down a building and eats a helicopter. If he does it right then it automatically points to the Ice cream truck option to reward him.
Then there's the discipline, which is Angelica kicking him!!
The bath/toilet is the same whatever he does (you don't see anything if he's pooed which is annoying. He just calls for attention and shakes his head, if you leave it long enough though it will make the toilet icon flash) When you select it the top comes off of a fire hydrant and you see him moving around in the shower of water and then it shows a baby (which one I don't know, it doesn't look like any of them lol) then it goes back to Reptar under the water again.
And last but not least there's the vet which is Tommy cleaning him off.
It's pretty cute, he doesn't actually move around on the screen left to right like my cat one does, but all those things I said you can teach him to do, he does as random animations when you're not doing anything with him.
I'll post a few pic links later for anyone interested.