If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Kevin suddenly appeared and kidnapped Gwen.
He demanded that Ben turn over the Omnitrix.
If his demand is not met in 24 hours, he'll kill Gwen.
The only way to find Gwen is to fight the way through the massive underworld before it's too late...
Good luck Ben, this is a one-man infiltration mission.
Gwen is waiting for you at underworld's end...