As I mentioned on the main page of the guide, I'm going to find and acquire every collectible in the game and I'm going to show you how to do it all with only a single player. Though I may not collect every last Lum or Skull Coin, I will collect every Lum Medal, Electoon, Time Trial Trophy, and Skull Tooth. For the sake of completeness, I'll also show you how to complete the parts of the game without any collectibles (e.g. the extra difficult "Land of the Livid Dead" level). Following my guide should help you score the Electoon Legend (for collecting every last Electoon), Nitro! (for earning every last Time Trial Trophy), and The Jaw! (for collecting every last Skull Tooth) Gold Trophies (among a wealth of other Trophies), effectively earning you 100% completion for the game.
If you're going to want to collect everything, you'll need to do most levels at least twice. When applicable, I split my recordings for the relevant levels into two videos, the first for collecting the initially available Electoons and the second for the Time Trial challenge.
Also, though I did not include audio commentary for this guide, I did include textual commentary that can be found below each of the corresponding embedded YouTube video players.