I suppose it differs from person to person when it comes to spoilers. I usually don't mind spoilers, while my brother detests spoilers.
However, the degree of spoiling depends on how much you've already figured something out: if the developers of a game has dropped clues about something for the first third of the game, and does the big reveal at the beginning of the last third, while you yourself figured it out during the end of the first half, it's not really a spoiler as much as a "Oh. So that's what they meant with all that", and less than a "Oh. THAT'S what was going on!".