How do you get all the secret achievements in Strike Force Heroes

Human Plug: go to Caverns and stand on top of the water geyser for a little while
Embarrassing!: go to Foundry and get your killstreak ready, die by the falling lava while using your killstreak (example: using scout and died while activating surge)
Waterwings: go to Caverns (Night Or Day) and CROUCH while being in the green water at the bottom of the map and die by drowning
Detective: go to the 5th level in the campaign, go into the RIGHT ventilation shaft when you get off the helicopter, drop into the room (You need to walk over the dead scientist)
Note that on the Detective achievement, you may have to restart the mission to get out of the room... unless I'm so blind that I can't see an exit...