Very high difficulty level. The game actually is rather short.
Still considered one of the top RPGs of all time, Shadowgate gained critical acclaim for bringing text-based interactive RPG gaming from PC to the NES. In the game, you played a warrior on a quest to unlock the secrets of the Castle Shadowgate, solving puzzles and finding ways to utilize items to defeat various evils inside the castle.
As is typically the case with NES RPGs, the graphics are very simple. Not much to write about outside of areas important to gameplay that stick out if you look closely. Music is generally the same background music you'll hear throughout the game but changes appropriately at times depending on the situation you're in. There are good sound effects for situations like using certain items or fighting enemies that add to the overall experience. Controls, given this is a text-based RPG, are exceptionally simple-you use a pointer to choose what you want to do, press the button, and the game does the rest. This actually still leaves a high level of interaction as you choose things like walls to hit, which door you want to go through, etc. There are lots of puzzles to solve, some trickier than others, and plenty of monsters & traps to deal with as well. A save option is also available so you don't have to go back to start everytime you mess up. On the downside, the game is not only very hard to beat, it's also surprisingly short. The castle is not nearly as big as one might hope it would be.
If you want a really hard RPG or something that makes you really think before you make your next move, this is a game for you. It's still one of the best RPGs out there and deserves a lot of credit for helping to launch a new style of RPG video gaming.