Great remake!
Although Icom/Infinite Ventures has already ported Shadowgate on the Game Boy Color; yours was a case of something accurate to the source material, but adds a few enhancements to make it better.
Graphics: It's the same as the NES version of the game, but you added to it with Flash 8's capabilities. To put it another way, what you did with Flash's tweening added to the experience, and kudos for managing to make shape tweening NOT look shitty. However, I think you could have taken the Flash enhancements a bit farther and some sprite editing would have been nice.
Sound: You did a great job at porting the game's music, though you could have used a greater variety of sound effects. For example, try Megatron's Laugh from Beast Wars upon the death screen.
Content: It may be a Flash remake of an NES game, but at least it was fun and that's what matters. In addition, you also streamlined the interface a bit and added mouse support, which makes this better. That, and an easier to navigate item menu. However, having to deselect a command can get a bit tedious, but that didn't affect playability in any major way.
What I like:
-Solid gameplay
-Good music
-Previously Unused subject
-Addicting
-Clever enhancements
What I didn't like:
-The enhancements could have been taken a bit further.
-Can get confusing at times, but still manageable if you know where to look.
Overall: Larry, how would you like a nine from me? (4.5/5)