I went to Target tonight to pick up an iTunes card and a pillow that hopefully won't go flat in a month, and they had Flashback units. They weren't with the regular Jakks Pacific type stuff, they were in the modern game console section. I couldn't help myself, I just had to get one. I want to know if it's any good.
This is Famiclone technology, plain and simple. I tried out Battlezone first, and it was nothing like the 2600 version. Colors were wrong, all the enemy tanks are facing you, instead of driving around and then turning to face you. The enemy tank's weapons fire doesn't follow proper physics like the 2600's tank fire did. The sound effects are a tip-off that it was Famiclone tech. But the real telling point was when I pressed the reset button, and the graphics broke apart, the same way a bad NES connector would make a game screen turn to gibberish. And the best way to tell that it's Famicom technology, Desert Falcon played like shit. The graphics were nothing like the original, the animation was terrible, and the graphics flickered like crazy and there was slowdown. A real 7800 has far better sprite handling abilities than the NES, and this is a good example of that.
Fast Food played like it was in slow motion. I've got the XE version, but not the 7800 version, so I don't know first hand if the 7800 game plays so painfully slow. The XE version didn't. And the Flashback shows how bad it's sprite handling is again, when more than a few sprites on a scan line makes big gaps disappear out of some sprites.
Yar's Revenge played the same, just with larger sprites and weird sound effects. The graphic effects, like the Ion Zone, and the explosion when you destroy the Qotile base, are completely wrong, and scream NES-on-a-chip.
Planet Smashers was fairly accurate, considering there's not a whole lot to the game. The obnoxious weapon sound effect is intact, unfortunately. The one thing they should have changed, and they didn't.

When you get to the boss, however, you are pretty much fucked. The boss stays right above your ship, and fires bullets at you at light speed. There's virtually no way to defeat it.
Adventure is a pretty strange one on this machine. They have all the elements, but things are..... a little off. Diagonal movement is a lot slower than horizontal or vertical movement. The sound of the dragons being slain honestly sounds like it was badly digitized from the 2600's sound effect. The bat moves like the proverbial 'bat out of hell', the chalice doesn't color cycle properly like the 2600 version's did, and the sounds when you finally deliver the chalice to the yellow castle are really bizarre. When, on the Atari 2600, you push the 'Select' button while the end music is playing, the music will slow down to about a third of it's original speed. Well, the Flashback's Adventure end music plays even slower. And clunkier.
I could spend all night trashing the Flashback, but I won't. I knew I shouldn't have bought it, but I couldn't stop myself. I had to see how bad it was for myself. In the same way that I had heard how bad the Intellivision 25-in-1 was, but I had to get one for myself. And i'll pick up one of Tulip Computer's Commodore 64 joysticks, too. My geek curiosity always wins out.