Challenge mode
Successfully complete the game to choose any level for game play.
View developers
Play the Civilian Base 1 level. Notice the room that cannot be accessed, but is visible on the map when you examine the second large room. This room is on the northern side. Aim manually and destroy all of the lights in the mission. When this has been completed, return to the northernmost big room on the map. You can now pass through the wall when Meteor Crashing.
There is a picture of development team in that room.
Upgraded suits for Kelly
Reach level 8 to get an upgraded suit for Kelly. Collect all of the Halley's Core Pieces from each level. After collecting the last one, she will evolve into Kelly level three.
Halley's Core Piece in Civilian Base 1
In the room that has the three plasma hook things, there is a small room near the roof of the area. The room is facing the way to the next room.
Halley's Core Piece in Civilian Base 2
Go up one level at the narrow shaft, then fall off the side. Go down by using the areas in the corners.
Halley's Core Piece in Civilian Base 3
Look for five SVN drones in a star formation after falling most of the way down. Enter the door on this level. The piece is under the platform just beyond it.
Halley's Core Piece in Naglfars Pit 1
Look under the platform that you start on.
Halley's Core Piece in Naglfars Pit 2
It is located in very middle of the level, on the ground.
Halley's Core Piece in Valley 1
It is located in the highest platform area of the second set of mushrooms.
Halley's Core Piece in Valley 2
Look in the floating platform area with the strong air currents, located above and to the right of the north exit.
Halley's Core Piece in Valley 3
Search in the area that looks like where the Drive Gun is found in the Valley 1 level.
Halley's Core Piece in Yggdrasill 1
Found next to the wall, about half way down.
Halley's Core Piece in Yggdrasill 2
Located next to the wall, about half way up.
Recommended purchases
Save your GVP to buy the D. Gun upgrade level. 2, P. Hook level 2, the Lock On level 2, as well as the Shield Gen. level 2. Do not bother with the level 1 items unless you feel that you will not be able to save that much GVP.