Are the symptoms of testicular cancer bad?

No: I think you are asking whether the presenting symptoms of testicular cancer are bad (ie painful?). Most men who present with testicular cancer present with a nodule or painless swelling of one testicle. About a third complain of a dull ache or heavy sensation in the scotal region. About 10% present with acute pain.

They can be: Usually testicular cancer presents as a mass in the testicle that may or may not be painful. Having a mass in the testicle may increase the chance of the testicle getting twisted around, which can be quite painful. Sometimes the pain from the mass can be referred (sort of transmitted) to where it is felt in the groin, the back, or the lower abdomen.