In my opinion, I think Sussex isn't "easy" to get into, but rather - an innovative university. They are less 'traditionalist' than other universities in the Top 20, probably since they're known for radicalism and left politics with a lot of student protests ongoing in the 60s (I think). They are more likely to look at each applicant on a case-by-case basis, rather than writing them off if they are in any way unconventional. I can't say this is true across the board, but I applied for English and got an offer, despite having a Diploma in Performing Arts from Malaysia. I am supplementing it with A-Levels, but still! Since you're applying for Media Studies, they will probably stress a lot more on your personal statement than your actual grades (not sure if they'll ask for portfolio or samples of previous work).
I'm unsure about their policy towards international students, but their prospectus does state that they aim to increase the diversity of the student population to have a more global learning, or something along those lines. I won't say being an international student will help, but I think they are more aware of our differences and circumstances in comparison to home students.