I adore fantasy, and I'm always happy when anyone takes a stab at it (pun intended), especially before the Lord of the Rings films and Game of Thrones TV show brought fantasy more into the mainstream.
That having been said, Dragonheart deserves credit for being a big-budget production with an excellent leading cast and (for their time) absolutely stunning special effects. It was also well-served by a brilliant and well-employed musical score.
Unfortunately, in my opinion the special effects don't really hold up that well. This movie was made 3 years after Jurassic Park, and rewatching JP I doubt you could make better effects today. With Dragonheart they did a decent job of making the dragon seem tactile (which is usually the biggest challenge), but the balance was that it came out rather cartoonish. It's possible this was intentional, but if so, it's another element of the film's inconsistent tone problem (discussed below).
I can overlook outdated or even bad special effects. I have a much harder time with poor scripting. I'm aware that they were trying to tell a big story in a short span, but some of the elements they try to rush through are really narrative-breaking. SPOILERS: In the beginning Prince Einon (Lee Oakes/David Thewlis) is summoned to witness his father's great victory over a peasant rebellion, and his teacher Bowen (Dennis Quaid) says there's no greatness in slaughtering helpless peasants. But when we actually see the fight, it's obvious that this is anything but an easy slaughter. The king has few men, they are completely disorganized, and the upshot is that this supposed 'easy slaughter' ends with the king being killed in the fighting. And then there's the 'great knight' Bowen, who forbids the prince to go down to the fight but isn't even competent enough to stop him from running off, or even to follow along and protect him so he doesn't end up nearly killed. Some knight! But further on in the movie (basically any time they're interacting with Kara (Dina Meyer)), they refer to the rebellion as a doomed slaughter. It's as if everyone has forgotten that even if the peasant's didn't ultimately "win," they did succeed in killing the evil king and nearly killing his heir! That's far from the complete failure it's presented as. These sorts of narrative-breaking things continue throughout the story.
MORE SPOILERS: Even though the audience is never shown Draco (voiced by Sean Connery), the characters are clearly looking him right in the face during the entire scene in which he gives the prince half his heart. Given that this appears to be the first dragon Bowen has ever seen, and that it moves him so greatly that he pledges his undying loyalty, one would think he wouldn't immediately forget what Draco looks like, to the point that after years of trying to hunt him down, when he finally finds him he recognizes neither the dragon nor his very distinctive voice. Better writing would have provided a reason for this, but Dragonheart simply expects us to accept that because they didn't show Draco to the audience, Bowen shouldn't remember what he saw either.
Even worse is the film's lack of consistent tone. It obviously wasn't intended to be grimdark, which is good. They're telling an uplifting narrative of redemption and heroism and idealism and friendship, and that's all to the good. But they're also trying to present a serious struggle, with evil bad guys we're supposed to take seriously and heroic good guys risking life and limb, which is why the film does itself such a disservice when it resorts to slapstick comedy, especially during what ought to be a dramatic fight between the dragon slayer and the last dragon, instead dissolving into a slapstick jokefest.
All in all, the story is over-simplistic, rushed, and inconsistent in details and tone, which unfortunately makes it rather disappointing.
That having been said, Dragonheart deserves credit for being a big-budget production with an excellent leading cast and (for their time) absolutely stunning special effects. It was also well-served by a brilliant and well-employed musical score.
Unfortunately, in my opinion the special effects don't really hold up that well. This movie was made 3 years after Jurassic Park, and rewatching JP I doubt you could make better effects today. With Dragonheart they did a decent job of making the dragon seem tactile (which is usually the biggest challenge), but the balance was that it came out rather cartoonish. It's possible this was intentional, but if so, it's another element of the film's inconsistent tone problem (discussed below).
I can overlook outdated or even bad special effects. I have a much harder time with poor scripting. I'm aware that they were trying to tell a big story in a short span, but some of the elements they try to rush through are really narrative-breaking. SPOILERS: In the beginning Prince Einon (Lee Oakes/David Thewlis) is summoned to witness his father's great victory over a peasant rebellion, and his teacher Bowen (Dennis Quaid) says there's no greatness in slaughtering helpless peasants. But when we actually see the fight, it's obvious that this is anything but an easy slaughter. The king has few men, they are completely disorganized, and the upshot is that this supposed 'easy slaughter' ends with the king being killed in the fighting. And then there's the 'great knight' Bowen, who forbids the prince to go down to the fight but isn't even competent enough to stop him from running off, or even to follow along and protect him so he doesn't end up nearly killed. Some knight! But further on in the movie (basically any time they're interacting with Kara (Dina Meyer)), they refer to the rebellion as a doomed slaughter. It's as if everyone has forgotten that even if the peasant's didn't ultimately "win," they did succeed in killing the evil king and nearly killing his heir! That's far from the complete failure it's presented as. These sorts of narrative-breaking things continue throughout the story.
MORE SPOILERS: Even though the audience is never shown Draco (voiced by Sean Connery), the characters are clearly looking him right in the face during the entire scene in which he gives the prince half his heart. Given that this appears to be the first dragon Bowen has ever seen, and that it moves him so greatly that he pledges his undying loyalty, one would think he wouldn't immediately forget what Draco looks like, to the point that after years of trying to hunt him down, when he finally finds him he recognizes neither the dragon nor his very distinctive voice. Better writing would have provided a reason for this, but Dragonheart simply expects us to accept that because they didn't show Draco to the audience, Bowen shouldn't remember what he saw either.
Even worse is the film's lack of consistent tone. It obviously wasn't intended to be grimdark, which is good. They're telling an uplifting narrative of redemption and heroism and idealism and friendship, and that's all to the good. But they're also trying to present a serious struggle, with evil bad guys we're supposed to take seriously and heroic good guys risking life and limb, which is why the film does itself such a disservice when it resorts to slapstick comedy, especially during what ought to be a dramatic fight between the dragon slayer and the last dragon, instead dissolving into a slapstick jokefest.
All in all, the story is over-simplistic, rushed, and inconsistent in details and tone, which unfortunately makes it rather disappointing.