Game Dev Tycoon [cheats]
Go to the bank and ask for a loan and then while signing the loan click on the signature location (with the 'XXX's) as fast and and repeatedly as you can. The more times you can click, the more money you will get from the loan.
Treasure Hunter Easter Egg
Activate the hidden treasure in the garage. This is done by making a game named 'Pong' while in the garage. When you code the graphics part the animation on the wall will play.