I'm sorry to hear that!, the characters vary in sprites sizes, but they are mostly 16x24 (width,height). with no 'offset'.
it's difficult to 'set up' a sprite sheet for every possible 'software' on the market, i did my best at the time i did these. As a Gamemaker Studio user, these work fine, but I get what your saying, I will try and do better, your comment is valuable feedback, because unless i know then i can't do anything about it.
What i can say, which might be better for you is I am currently reworking the sprite sheet as we speak.
I'm adding more animations( This image is of the SMS version, not the GB, but there will be a GB version) and making them better, at least i hope.
Now what i am going to do is not only have the Sprite sheet, but i am going to include individual 'Strips' of each animation that will be available, this way it will be better for importing without the 'Leg work' of tediously grabbing each single frame to create a strip yourself. I will within the sprite sheet check the spacing. Would this be better? or if there is another/better way, then let me know, i'l be more than happy to do it, or at least try and see if its more supportive for the software you are using.
These wont be ready for at least a week though.