It can suffer in a number of different ways.A question- Ive been playing with the kit for a while now, and I have discovered that when I tap the board right by the 555 timer, it moves to the next LED in the sequence. When you fry a chip, what happens to the circut with the chip?
Holding heat on a pin for too long is one easy way to kill an IC. If it doesn't take solder after ~3 seconds, then your iron is dirty, tip is loose, iron not hot enough, or your parts/pads are not clean. Holding the iron on a part and pouring on the solder just won't help things at all.
If you are certain the soldering on the 555 is good, then you may have overheated it enough for a substrate bonding wire to pop. Replace the 555 with a new one and see if that takes care of it.