Walkthrough by Measure76
Version: 2.0 | Updated: 11/16/2018
This guide is specific to the Shadow Complex Remastered version of this game that is on the Xbox One. It may also work well for other platforms, but the XB1 is the platform I wrote it with.
This guide can be used to complete the game in 2 hours and with 100 percent of items. This unlocks the Jason Bailey Badge and Achievement, which is a nice throwback to Metroid. It can also be used to complete the Chairness Badge and Achievement, which is 100 percent in 3 hours or less on insane.
This guide will not work for the original version of the game. There is a guide in the XBOX 360 section by Elbarto2003 which is excellent for obtaining the same achievements on that version, though it takes about 10 minutes longer because some extra backtracking is required. This is due to a bug with the first intended missile pickup, where you can't pick it up in the original version if you already have missiles in your inventory. Still, with some practice his guide is very doable.