I’ve been playing Game dev Tycoon and played some some games and for some reason randomly I receive a research feature saying . Unlocked researches: Mouse. I don’t know how to get it and in my save I having problems obtaining it because who likes to play a video game on a PC with a custom engine that requires a gamepad not a mouse. TLDR? So: how do I get the mouse feature?
First you have to research those features and then you have to make a new engine.
What features?______
Research “mouse” through the normal research menu, then create a custom engine and make sure you select “mouse” before you make it.
Yes but the problem it isn’t on the normal research menu! 
Have you researched it already?
Check in "Create custom engine if it’s available
The problem is that it isn’t appearing an option to search it!!!
You need to research Joystick first.
Thanks! ------------