Object rotates after applying movement control scripts

Hi guys need some help over here. I'm new into unity and i have to make a spaceshooter for my class. I already done some thing like move the player detect collisions, instantiate asteroids and enemies... and now I was trying to make some visual changes by using new assets.
The thing is before everything was running smooth but now when I put de new ship on the scene and put then movement control script then ships rotates itself. Any ideas why this happens??

 

Maybe the asset has its own scripts? Maybe there's some colliders interacting that you didn't have before?