Near the end of my work on the Shrek 2 GBA TAS, I decided to spend a bit of time looking at Shrek the Third GBA. Shrek the Third has fairly similar basic mechanics to the original, with multi-character levels and locating keys to progress in levels. However, there are also a lot of differences: you have a different cast of characters (Gingy is replaced by Arthur), the basic physics are very different (holding 'A' to jump jumps higher), and the basic progression requires you to collect a certain amount of fairies to get to the next world. The game also has some of the new innovations from Beg for Mercy, like more abilities for Puss and automatic key pickups.
I have to say, I really don't understand this game very well. I haven't looked into the fairy threshold recently, but I know you don't need to collect them all for any%. 100% is probably easier to route because you just collect everything instead of being more discerning. There are also optional special abilities each character gets after collecting 4 specific objects. There used to be fairly detailed speedrunning resources two years ago, but all of the links have died since then. Almost all of the speedruns were dead links as well, thanks to Twitch not automatically saving VODs. Fortunately, someone did a decent speedrun a few weeks ago:
Link to video
I also used rewind to get started on a TAS, but it's kind of a mess. The early levels are particularly bad, but my entire playthrough has routing issues. Theoretically, I was aiming for 100%, but I missed some required objects and fairies. Most likely, I'll try and update this with a file that finishes the game, and then take a break for a while. I might just take a break before finishing a complete movie, though.
My movies: 001 (19 July 2023, 25:42.04, through 3-3)