Takes a while to get into but once you are there it is very hard to put down.
Essentially, all you have to do is make a line of three or more animals in the game grid and keep doing that until the level ends. Nothing too hard there then I hear you all say.
There are several game modes, each offering a different style of play and a different outcome. The main mode is going to be 'normal' though so I would start there.
I think that the reason it is actually quite a good fun game to play is because it is so simple. There are no real problems or puzzles to have to figure out and reaction time does not really factor either.
Sound is acceptable for a game of this type and I personally think that the game does look quite nice and maybe a little bit retro.
I woudl advise trying to find a copy of this game and giving it a try, it is actually really good fun.