Cookieboy is a Gameboy emulator written in C++. 

Main features:
-Gameboy and Gameboy Color emulation
-Full CPU emulation with accurate timings. Passes all blargg's CPU tests (opcodes and timings).
-Accurate memory timings emulation. Passes blargg's RAM timings tests.
-Full emulation of several ROM MBC's: MBC1, MBC2, MBC3 with RTC, MBC5, MMM01. 
-Supports battery powered external RAM.
-Full LCD emulation. Background, window, sprites.
-Pretty accurate LCD controller timings emulation with OAM and VRAM locking. Passes blargg's lcd-sync.gb test.
-Accurate sound emulation. Passes all blargg's sound tests - DMG sound tests and CGB sound tests in both DMG (with proper error codes) and CGB modes.

Key mapping:
Up:     Up
Down:   Down
Left:   Left
Right:  Right
A:      Z
B:      X
Start:  S
Select: A

Debugging helpers:
F1:		Toggle backgroud
F2:		Toggle window
F3:		Toggle sprites
F5:		Toggle sound 1
F6:		Toggle sound 2
F7:		Toggle sound 3
F8:		Toggle sound 4

By default emulator runs at normal Gameboy speed. Press "Space" to run at maximum speed (depends on your PC).