Agreed, the game can be confusing if you don't know what to do. I'll give a quick explanation here:

There is a chaos meter (the big green bar) that is constantly increasing. If the bar fills up completely, you lose the game. In order to bring the bar down, you have to constantly complete the six microgames that are sporadically activated (you can see this by looking at the lights which turn red if you need to fix it).

There are six microgames: 

• Color Switch (top left): All nine of the tiles must be the same color as the indicator right below it. Change the color by clicking on a tile.
• Pressure Regulator (top middle): All three gauges have to be filled by clicking on the buttons below them repeatedly, until they are all simultaneously full.
• Temperature Regulator (top right): The temperature has to be set to the desired amount. You can change the temperature by clicking on the +1 and +0.1 buttons. If you overshoot, click on the reset button.
• Rewire (bottom left): Every lightbulb must be dragged to the socket of the same colour. Click and drag to move lightbulbs.
• Levers (bottom middle): All levers have to be up (also indicated with a green light). Every lever that you click changes the levers in a particular way, try to figure out what they all do.
• Fuses (bottom right): All fuses have to be on at the same time. Click on a fuse to toggle it on.

Every completed microgame gives you a coin, which you can use on the three buttons to the right. These buttons will finish a certain amount of microgames for you and bring the chaos meter down.