Your data is transferrable from Castle Crashers on Xbox 360 to Castle Crashers HD on Xbox One. This requires both an XBL connection and an Xbox 360.
1. Start Castle Crashers on the Xbox 360.
2. Go into Player Statistics from the Main Menu.
3. Hit Right Trigger to "Upload Save for Xbox One".
4. Start Castle Crashers HD on the Xbox One.
5. Go to Player Statistics from the Main Menu and hit Right Trigger to "Download Xbox 360 Save Data".
This will transfer all character unlocks, weapons, items, animal orbs, levels, game saves, and silver/gold skull progress. Consumables such as gold, potions, bombs, and sandwiches will not transfer.