A perfect example of frugality, Cursor*10 is a wonderful little Flash game, featuring time-manipulation gameplay. The game's objective is to reach the 16th floor. To go up one floor, click on the stairs. Click on pyramids to earn points. But on some floors, stairs are hidden, and you have, for example, to click two or more switches at the same time for them to appear. How can you do this, if you are playing alone and there's no possibility of pushing objects around? You have ten cursors. Each cursor has a lifespan of about 30 seconds, during which it's movements and clicks are recorded. Then another cursor appears, while the previous one(s) replay the sequence of actions you previously made.
The game has no music or sound effects, about 4 art assets (the switches, the pyramids, the unfolding boxes, the stairs) and can be beat in less than 3 minutes; yet it is considered one of the best Flash games around.
This is not the first game in which the player movements are recorded and then replayed: as soon as in 1992, the Time Trial mode in Super Mario Kart let you compete against yourself. But Cursor*10 uses this gameplay resource for self-collaboration in a clean, easily understandable way.
You can play Cursor*10 here.
And if you have some spare time, I highly recommend you to check other Nekogames works.