The game I chose the analyze was A Daily Cup of Tea. (The current location of this game is the first row, sixth game across, with a pink teapot on a brown striped background.)
The gamer is presented with a multi-level vertical playing surface across which are the targets he needs in order to score. He uses the keyboard to control two characters that move in tandem horizontally but can run on two adjacent layers at the same time. Once the player contacts with all the targets, he is moved to the next level, which presents progressively more vertical layers with additional targets. Subsequent game levels also present "enemies," some that attack horizontally, others that drop vertically.
The two characters would be two instances of the same object, in particular since they are controlled by the same player movements. They also seem to have some amount of internal animation, since they appear to "run" as they move across the shelves. When the player wants to move a mouse to a higher shelf, there is additional animation that is called as the one helps the other to the next shelf.
The sugar cube targets use an event listener to perform a hit test. Upon being hit, the targets are animated individually to spin and are subjected to "gravity" so they appear to fall off the shelves.
The hit test also activates a score keeping mechanism to increment. It's possible the the scoring mechanism is also what tells the game when the level has been completed and all of the sugar cube targets have been hit. This way, rather than tracking the location of all of the targets, the score-keeping tools knows how many instances of the sugar-cube targets exist, so it knows that when it reaches the predetermined number in the count, it is time to advance the player to the next level.
There is also hit testing going on related to the "enemies"--the falling books and the flying bumble bees. Upon the first hit, both mice change state to a half-saturation version and a timer is initiated. If either of the mice is hit again before the timer hits a predetermined duration (say, 15 seconds), then the player's game is over. Otherwise, once the timer exceeds the limit, the mice characters are returned to their full state.