What am I to do when something appears on one of the levels

the-binding-of-isaac

After playing some more the Binding of Isaac I've come across strange messages that are triggered by certain events.

For instance, when I defeated one of the bosses, I suddenly got a pop-up message that read something along the lines of: "A radioactive spider has appeared in the dungeon" (there was also a drawing of a spider on that message).

Another time, after taking a yellow pill, I got a rather enigmatic hint that said "bombs are keys". I then proceeded to blow up a strange looking rock, only to be greeted with another pop-up saying: "A small rock has appeared in the basement" (this time with a picture of a block. I don't know if taking the pill was actually a prerequisite to get this message).

What do these messages mean, exactly? What am I supposed to do once they appear?

Best Answer

I own the game (on Steam, not even sure if a retail version exists..). The popup messages like "small rock has appeared!" notify you that you've unlocked an acheivement, that's all. Some acheivements have rewards, though.

I'm equally confused about the bomb message, though.