Summary
Boring, non-RPG, non-adventure, repetitive, simple, cheap.
The Good
As you explore your surroundings, each area must be uncovered by your character as you walk. Even though this feature is not one of a kind, I can still mildly appreciate what SEGA was attempting here.
The Bad
The music isn't too bad, but it continuously repeats throughout the game, only changing a total of two or three times. The battle controls are horrible and awkward. To attack your opponents, you must use the directional pad. There is no strategy or skill involved. None. Also, this is supposed to be a cross between the RPG and adventure genres, but falls painfully short of both. The few RPG elements that exist are so vague and incomplete that they might as well not be part of the game at all. There is absolutely no storyline whatsoever. In addition, there is this egg that follows you around, which then becomes a dragon, does absolutely nothing, and continues to follow you. What is the use of this? Worthless.
The Bottom Line
Dragon Crystal is cheap, in every way. It is extremely obvious that the developers spent no more than two or three weeks creating it.