Yes, you can pre-order games on ENEBA! All you have to do is purchase a pre-order product and wait until the day that the game is officially launched. You will receive the code on the day the game is officially available. You can check the release day on the product page of the game you want to pre-order. Keep in mind that due to time zone differences or possible technical difficulties there might be delays delivering the key to you.
NOTE: There is no guarantee that official pre-order bonuses will be included, unless they're clearly mentioned in the product description on ENEBA.