Another classic from the time that Superior released Beeb versions of all the arcade greats and users were so vaught up in the newness of it that minor flaws (like speed) were overlooked.
Percy Penguin is, of course, a Pengo clone - no better and no worse than many others. On a screen of sliding ice cubes, you have to kill the deadly Snobees by hurling ice cubes at them and so squashing them flat.
Another ecologically sound idea, no doubt. The game still plays quite well but is, sadly, very dated now. However, at the price, how can you go wrong?