Ducks is a classic game by Tim Furnish and Hungry Software. Ducks is a Lemmings clone that used to be shareware and is now freeware. A DOS emulator like DOSBox is required.
Instead of clearing the path to a portal for green creatures, the player controls a green duck, the leader of oranges ducks that must be guided to a rocket ship. Clicking and holding the right mouse button on any place of the game field makes the leader move towards it. When the green duck is close enough to the orange ducks, they start to follow it. Moving the mouse while holding down the button makes the green duck change direction accordingly. The rocket ship has a number on top, indicating the number of ducks necessary for it to take off.
Numerous hazards scattered through the levels kill the ducks. Instead of Lemmings' more aseptic approach to violence, deaths on Ducks are quite gory, with the animals exploding and their blood splattering on nearby surfaces. A slimy monster wanders some levels and devours the birds, and they can also be murdered by spikes, fans, electric bolts, and long falls. Switches turn off and on the electric arcs, but can only be activated by the leader, and only once per level. The ESC button makes them commit suicide, useful to quit a level made unsolvable by wrong actions.
Several tools help to clear the path to the rocket. They appear as icons at the bottom of the screen and can be changed with the arrow key and deployed with the left mouse button. The bomb explodes the scenery, removing chunks of it each time. Horizontal bridges and diagonal ladders help the ducks to cross safely over chasms and dangerous environments. The balloon acts like the bomb, but it goes upwards instead of falling. Stop signs make the orange ducks stop their march, instead of walking toward deathly devices and places. Bricks can be placed on top of each other, to construct bridges manually. The teleport transports the leader anywhere in the level. Seagulls and flying saucers replace the leader, guiding the birds and moving automatically from one side to the other (the saucer goes up and down as well).