Hey guys, lets say I've done extremely badly for 1 or 2 subjects
at the A levels, while the rest are of decent grades - As and Bs,
can I retake the lousy subjects alone next year? Or do I have to
retake everything before I can apply to the Unis?
Quoted : At
least two passes in subjects at H2 level and attempted General
Paper (GP) or Knowledge & Inquiry (KI) in the same
sitting;
http://admissions.ntu.edu.sg/undergraduate/singapore/admission/Pages/CategoryA.aspx
http://www.nus.edu.sg/oam/apply/local/admissionreq/BYA-admission.html
If you do not want to share your grades openly, feel free to pm
to dkcx/TrueHeart and they will advise you on what course you may
be able to take. 
I am not saboing them, and I will have suggested myself, but
since I will be busy mugging for my end-of-semester exam, there is
no telling when i will login again.