I've been pretty unimpressed by the plethora of direct-to-tv games I've tried. Most of them appear to be poor emulators of the original. It will never cease to amaze me how "amateur" programmers can write emulators that blow-away "professional" ones. My first impression of the JAKKS Pacific TV Games Mortal Kombat was disappointing. I thought it was basically the Genesis version. That was until I went back and played the Genesis, Super Nintendo, and Sega CD versions again. This direct-to-tv gizmo is better than all three by a healthy margin.
Play control:
This is near-perfect in terms of replicating the feel of the arcade game.
Graphics:
My understanding is that this is essentially a "Genesis on chip" but it's clearly not running the Genesis ROM. The backgrounds are more detailed, characters more colorful, and animation smoother.
Sound:
Pretty accurate conversion of the original soundtrack.
Other Factors:
The controller itself is bulky and uncomfortable after a prolonged period.