This game, as I'm writing the most recent in this collection, is simple but
very well realized.
It consists of a board made of squares with some bubbles on it. The goal is to
empty the grid removing all the bubbles.
With an arrow cursor we can point a cell and click it. This reverses the state of
that cell (empty if there was a bubble and bubble if it was empty) and of the
neighbour cells in the four main directions (up, down, left and right).
The time is limited and while we think about the next move, a counter
rapidly decreases. After finishing the first level there is a second more
difficult to deal with and so on. A password helps to avoid starting
from the first level every time.