Early on in Game Dev Tycoon, you're developing games from a garage. After your first couple of games you unlock the ability to research and create your own games engine.
The threshold to move to your first office is to generate 1 million in capital which can be reasonably easily attained without ever creating your own game engine.
Does using your own game engine effect your sales and review scores sufficiently enough that I should aim to research and create my own game engine as soon as the option is available, or can I wait until after I have moved to my first office and spend more money on a game engine with more features?