However, you have to remember that this action should only be done with games that require closing and reopening of the lid. It has been reported that minimizing/restoring of the emulator for games that does not require this action just leads to the abnormal behavior of the emulator itself. Usually, the emulator will freeze or hang up. To be able to get back into playing, you just have to minimize/restore it again.

When using No$GBA emulator, how would I be able to close the lid?
There are certain games from the DS that would require you to close the lid. When it comes to the use of the emulator, you just have to minimize it to be able to close the lid. When you need to reopen it, you just have to restore the emulator. However, doing this would result to some disadvantages. At times, the game hangs up or freezes due to this action of minimizing and restoring the emulator. This will not be gone for the game, of course.