To get a Hardware Engineer, win the Grand Prize and the Game Awards to unlock the monkey applicant. Alternately get a level 1 employee to level 5 in four different specializations.
Hire New Workers for Nothing
This can be done by doing the following. Use the 'Word of Mouth' hiring. When ALL your spots are filled get the best possible hiring you have. You can now fire whoever and pay nothing for new workers when you are told you have to fire someone.
How to Remove the 'PREV' Symbol
The following glitch removes the 'PREV' symbol allowing you to use a specific employee an unlimited number of times to do a certain job of game making (scenario, graphics, sound). When you are going to make a game and you are prompted to pick an employee to choose a scenario, press 'back' on the bottom right. When you tap 'OK' again on the 'Game Direction' window you will be prompted to pick the employee again and you will notice that no employee will have the 'PREV' symbol anymore.
Preview Result of Genre/Type Combination
To be able to do this select a combination of Genre & Type and continue until you are prompted to choose an employee to make a scenario. If you then press 'Back' on the bottom right and you will be able to see the result of the combination of Genre and Type without the need to create a game allowing you to search for 'Amazing!' combinations.