Gunvalkyrie Challenge mode: Successfully complete the game to choose any level for game play. Hint: Upgraded suit for Kelly: Get to 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 evolves into Kelly level three. Hint: Civilian Base 1: Halley's Core Piece: 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. Hint: Civilian Base 2: Halley's Core Piece: Go up one level at the narrow shaft, then fall off the side. Go down by using the areas in the corners. Hint: Civilian Base 3: Halley's Core Piece: 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. Hint: Naglfars Pit 1: Halley's Core Piece: Look under the platform that you start on. Hint: Naglfars Pit 2: Halley's Core Piece: It is located in very middle of the level, on the ground. Hint: Valley 1: Halley's Core Piece: It is located in the highest platform area of the second set of mushrooms. Hint: Valley 2: Halley's Core Piece: Look in the floating platform area with the strong air currents, located above and to the right of the north exit. Hint: Valley 3: Halley's Core Piece: Search in the area that looks like where the Drive Gun is found in the Valley 1 level. Hint: Yggdrasill 1: Halley's Core Piece: Found next to the wall, about half way down. Hint: Yggdrasill 2: Located next to the wall, about half way up. Hint: 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.