So, are you still wondering whether watching the anime would spoil the game ? Well, i must say both is very different. If you're still unsure, then you can check some of the comparison i listed below :

Difference:
- Zola didnt appears after much later in the game. In the anime she already shows up since the first episode.
- In the anime Zola is travelling together with Jiro. In the game, Shu started with both Jiro and Kluke.
- The way they obtained their dragon power is much different
- It stated in the anime that Jiro's village is destroyed. Well, in the game, Jiro lives in the same village with Shu and Kluke (they have their own house in the Tata Village which you can explore later)
- Jiro's attitude towards Shuu in the anime...looks like they hated each other or something
- Marumaru...god, he's such a pervert in the anime...flashing Kluke's panties and all
- I think there are many anime-only characters which doesnt appear in the game. For example ; Boquet.
- The Story is different.
- In the anime, the dragon each has different colors (the most notable is Marumaro's dragon). In the anime, all of the has light blue color.

- More will be added as i found them. Keep checking back !

Conclusion:
Since the game won't be released until August in the US, i guess it's safe to say that you can watch the anime without spoiling the game. ;)

Game: Shu vs Jiro works together as a team...

Anime: Well, their relationship isnt that good on the anime :/..

Anime: Perv Marumaro ? -_-