Kindly state why you felt so bad about this company that you have contracted? Are they ill-treating you? if yes, you can file a formal complain to
MOM.
SMEs do have their pros and cons. Infact you might learn and exposure to much more as most SME are lean and small without many levels of management and red-tapes to go thru.
As for performing badly and waiting to be sacked. That the worst idea. Ask yourself, how big is Singapore. You never know the bad name you create for yourself now will come to haunt you years later. So please don't. Always exit nicely.