Hopping is what frogs do, so it's no surprise that Hopper is another version of Frogger. The object of all Frogger games is to manoeuvre frogs across busy roads and dangerous rivers, without getting run over, eaten by crocodiles, or otherwise terminally squelched.
In this version, you have ten frogs, and the highway has six lanes. Traffic moves at different speeds in each lane, so that any gaps in the traffic are transient. On the other side of the highway, there's a railway, where trains sit around until, generally at the most inconvenient time, they are shunted away.
Then there's the river, where drifting logs and turtles can be hopped upon, and crocodiles and drowning avoided. If you manage all these, there are five safe lily-pads to reach. When they're full, the hazards gently escalate.
The frog can be moved with a Kempston joystick or with the keyboard, and the latter is actually easier since it reduces the rather high incidence of hopping two lanes when you only wanted to hop one.
Unlike real life, it's easy to get run over by the back of a receding car, and once you've hit the road, you can't hop back to the starting side again. As for sound effects, there's frog croaks as well as some irritating musical themes - for some reason, 'Rule Britannia' is played if you drown in the water!
But this is unfair - Hopper offers much in the way of obstacles, it runs smoothly, and it has clear graphics. Frogger has spawned many versions, and this one leapfrogs others. Hop out and buy it.