It's graduate entry to medicine, it's NOT a postgraduate course...it's still an undergraduate degree. Which is why it doesn't belong in this, the postgraduate forum.
Yes, it's more competitive, yes it's bloody hard work, and it's clearly doable since hundreds of people get in every year, but that still doesn't change the fact that you shouldn't be considering it until you've explored every non-GEM option i.e. working hard to get the right A2 grades.