This is an emulator started as a short experiment to test how feasible it even was to pull off such a thing in JavaScript, and quickly improved to support many more games and features than I thought it possibly could, but it is also still evolving.
If you see any glaring issues with certain games, or other support you'd like me to add, feel free to drop me a line, and I will probably bump up the priority.

~ Sumez

Features currently in the pipline for the future:

Support / accuracy:

• Support for less common mappers (most notably VRC6 and MMC2 I guess?)
• Controller support
• Improve mouse support
• 50hz/PAL support
• Famicom Disk System support
• Improve CPU/PPU cycle synchronization
• All unofficial opcodes
• Better CRT shaders (correct scanlines, color bleed, etc)
• Debug features (look here for some testing features, like nametable, CHR and wavetable displays)
• Save states.... maaybe?

Technical improvements

• Better performance across all areas (most notably PPU emulation)
• Average audio samples to improve quality and smoothen out high frequent tones
• Re-implement mappers to actually map addresses, rather than just copying data around find a new way to do this without a huge performance overhead
• Change PPU emulation to use actual PPU registers rather than abstract variables that don't interfer with eachother in the same way