By saying buggy, do you mean software has a lot of bugs but not crashing and running? If so, go on and report all bugs. In this condition I offer you, not to start anymore testing effort until 3/4 of the bugs are fixed. Even if a new release comes with say half of them is fixed, just do a regression and check the fixed bugs only. This will save a lot of time for you. I hope this helps.
First of all we need to do some smoke testing and be assure that software is stable so that we can continue with further testing.
If the software is so buggy,just report the blocking and major issues.Report them to developers even after you have raised the bugs in some bug tracking tool.Its a good practise.
Just intimate the developers to make a another release with bugs fixed.
I do smoke testing,sanity testing than come to complete testing of the software.This is my approach.I have prepared the documents like that.Which were very impressive to all.Till now no project had such documents in my organization and i was appreciated by the leaders for them in my current project.....