The guide drags the reader through the game alright, but I think there are several handy tips and tricks this guide is missing.
The most jarring advice I've read, though, is to use energy form in The Gauntlet 95% of the time. The one thing that makes The Gauntlet a lot more manageable, is the use of the dual form scream attack. it requires some practice to get it right, but creams can kill entire screens full of enemies, even very tough ones, in one move. It takes 2 screams to kill an abandon.
Things this guide is missing are, for example, the clever use of the nature form's ubervines. You can much more easily kill mossheads with them, as well as several bosses. The creator form 1 can even be killed by one well placed ubervine. They can easily kill the eye-blobs in the cathedral. (it is worth mentioning for those who go for kelp forest first) And the Giant Arnasi Crab can be killed entirely with ubervines, skipping past the other fazes of the fight.
The use of spirit form to absorb energy shots, absorbing 5 shots heal 1 HP. This is very useful in missile filled areas such as The Body and The Gauntlet. Using the environment optimally in your favor. Abandons are health dispensers.
A lot of boss fights where you do need to use energy form, can be made a lot more easy by consuming something that increases energy shot damage, the selective use of zunna's perogi can even make it so you only have to go through one cycle before a boss goes into critical mode.
Also, a lot of enemies are really not worth the trouble of fighting. Your guide gives the impression you need to be in energy form for 95% of the time throughout the game, and shoot everything, but you can very often get away with song form plus shield, and outmaneuvering enemies. There are a lot of things the shield can deflect, the shields breaks after a certain amount of damage , but you can easily recast it, especially if you use the keyboard shortcut to cast it.
If you are not blasting shots, you are free to put your attention to avoiding being hurt, this makes getting through areas a lot more easy. Most enemies will respawn anyway, and you don't need to kill them to earn XP or something like that.