I just finished Dragon's Curse for the first time. I really enjoyed it. Nice graphics, fun level design, and I liked the character switching dynamic.
The one thing I didn't like was how the potions were handled. When you load a game, all your potions are gone, so you have to go back and get more. Then, when the potions are used, you can get anywhere from 1 to 8 hearts refilled. When I battled the Vampire Dragon the first time, I used three potions, which refilled a TOTAL of five hearts. I went down in flames. The next time, the first potion refilled all my hearts.