There are four unlockables in this game.
Unlockable 1[edit]
The first unlockable is concept art. You will get this unlockable when you collect the first scribe's quill. There are 40 quills to collect and once you have collected all 40 you should have all 100 pictures
Unlockable 2[edit]
The second unlockable is more health. You will get more health when you collect the red dragon relics. This will be helpful when you verse Gaul.
Unlockable 3[edit]
The next unlockable is extra energy. You will get this unlockable when you collect the green dragon relics. The secend part of the battle with Gaul will use up all your energy so this is really helpfull.
Unlockable 4[edit]
The last unlockable is dark spyro. You will get this unlockable once you have completed the dragon challenges at the extras option at the main menu once you have completed the game.