Hey, 

Simple question. Currently I have a picture as a cover for my game, but I feel like it's not very appealing. So my question is, if this gif would be more appealing?

current cover:

gif: 

Let the cover be a cover. :) Keep the static version. It's more expressive, and as a bonus doesn't make me dizzy. You can put the animation on the game page as a screenshot, where it can work better.

^ Ditto. The gif is great to get a feel for the gameplay, but it lacks the fun personality of your static image.