Heres a Beta Release of a Nintendo GameBoy Advance Emulator for WIndows, heres the release notes:

mGBA Git (2018/03/11) is compiled. mGBA is a new emulator for running Game Boy Advance games. It aims to be faster and more accurate than many existing Game Boy Advance emulators, as well as adding features that other emulators lack.

* Near full Game Boy Advance hardware support[1].
* Fast emulation. Known to run at full speed even on low end hardware, such as netbooks.
* Qt and SDL ports for a heavy-weight and a light-weight frontend.
* Save type detection, even for flash memory size[2].
* Real-time clock support, even without configuration.
* A built-in BIOS implementation, and ability to load external BIOS files.
* Turbo/fast-forward support by holding Tab.
* Frameskip, configurable up to 9.
* Screenshot support.
* 9 savestate slots. Savestates are also viewable as screenshots.
* Video and GIF recording.
* Remappable controls for both keyboards and gamepads.
* Loading from ZIP files.
* IPS and UPS patch support.
* Game debugging via a command-line interface (not available with Qt port) and GDB remote support.

mGBA Git Changelog:
* Qt: Simplify display sizing
* Qt: Simplify window background drawing
* GBA Memory: Fix AGBPrint running out of memory on Wii (fixes #1001)

more info