AA member SmittyB has just released a new homebrew for the Atari 7800: Plumb Luck! The game is still a work in progreess. The difficulty is not particularly well balanced, there's no audio at the moment, and he wants to randomize the start / end tile locations at some point as well as add obstacle tiles.
You initially get 30 seconds before slime starts running through the pipes but a second is deducted for each stage down to a minimum of 5 seconds. You can freely place tiles over any other tile as long as the slime has not yet reached it.
Directions = Move cursor
Button 1 = Speeds up cursor and starts game
Button 2 = Place the left-most tile in the 'Next' queue at the current cursor location
Pause = Pauses (as one might expect)
Select = Skip the delay before slime starts coming out of the pipes, hold to speed up the slime and release to resume normal speed
Hi-Score = Your highest score so far (scores are not saved when the console is turned off)
Score = Your current score this game up to a maximum of 9999
Next = The next four tiles you can place in order from left to right
Stage = The number of X marks indicate the number of stages you have completed up to 20
Slime moves through an additional pipe section = 1 point
The stage is complete and the Slime runs down the drain = 10 points