Enter TINKERTOY as a code.
Enter EUREKA as a code.
On the Aquem level, there is a waterfall near the beginning. Walk through it, and you will find yourself at the end of that part of the level.
Zap the television in Muto's house to get 10 Isotopes.
In the junkyard, zap the dogs and vials will appear. Then, shoot them to get two more.
Enter BEAMMEUP as a code.
Enter CHEATERBOY as a code.
Enter LOGGLOGG as a code.
Enter BUZZOFF as a code.
Enter NECROSCI as a code.
Enter HOTTICKET as a code.