Bugs and cheats listed below can be replicated on a device without the need of cheat tools.
You can remove the "prev" condition on an employee when you create a game. When the screen comes up asking you to write a scenario, press back. This will completely remove the "prev" condition from the employee. This allows you to use the same employee again and again.
[Patched]When starting a new game, pick a genre / type combination. Press okay and then okay again until a dialog window pops up asking you to write a scenario. Press back and then repeat but picking a different type and/or genre. Wait a while and all of the genres/types will all level up. This makes leveling genres and especially types very fast.
For newer versions, this doesn't seem to take effect until development starts.
[Patched]Contract fees (hiring fees) only apply when you are filling an empty slot. You hire someone with a low contract fee and then replace them with a more expensive hire without having to pay the hiring fee for the more expensive one.
When you fire an employee exactly when he's going to give Research Data to another employee (it requires high reflexes), the other employee gets frozen and does nothing anymore. The only cure to this bug is the following: An employee goes to the frozen employee; The employee gives Research Data to the frozen employee; He becomes no more frozen.
If you fire a person like a hardware engineer (LIke John Gameson), You dont even need to hire a large money hiring task but instead hire him/her where you hired him/her before you actually fired him. Then if you luckily get the person you just fired, you can pay the amount that you hired him when you first hired him (John Gameson only cost $50 on Word of Mouth), you get the job that he/she was before you fired him.