Can mead spoil? If so, in what ways? Based on my research it seems like mead just flat out doesn't spoil, but since I didn't see this specific question here I thought I'd throw it out there to confirm.

I bought a bottle of mead just under a year ago, that I've had sitting in my kitchen since then. Initially it likely spent most of it's time at room temperature, and being exposed to sunlight every day. Then in the summer it would have been exposed to temperatures in the 90's and up for a few weeks.

Before I open it and try it, I wonder if my bottle is likely to be bad? And if not, are there other ways it can spoil?
Generally speaking, your mead is fine if you haven't opened it.  Normally, commercial meaderies bottle in dark bottles (or something other than clear) which keep out the UV light.  I doubt that the temperature was much of an issue.  You should be able to chill your mead and enjoy it.  FWIW, I'd drink it out of a wine glass made for white wine rather than the skull of an enemy.  You'll be able to pick up on the subtleties of the mead this way, while the other might be more enjoyable.