Now that I have played and beaten The Guardian Legend (I enjoyed it, except that the Corridor 3 boss was too difficult for that point in the game), what should I play next?

Here are the games I am looking at:
* Hollow Knight
* Momodora: Reverie Under the Moonlight
* Final Fantasy 5 Advance (replay using a new glitch I learned about recently)

Any suggestions?

Hard to say. Those seem to be storyline driven and not the kind of games I like, such as turn based strategy. Try sid meiers colonization 94'!

I'm not really into games where you have to coordinate the movement of multiple units.

I tend to prefer:
* Turn-based (or approximately turn-based) RPGs that don't make positioning a core game mechanic.
* Action games, as long as they're 2D.

Other notes:
* I prefer 2D to 3D.
* I don't like the isometric perspective.
* I don't like Baldur's Gate style gameplay, so games like that are out.

I just went to a protest on saturday, actually.

Of the ones you list I would cost Hollow Knight, because I am curious about it.

However, I recently got Into The Breach, and I think you should get this game. It's wonderful!

2D Action? Have you tried Broforce? That game is so much fun and hilarious too. Well done with all the different characters (Bro's) you play as well. Personal faves (not their bro names) are RoboCop, Predator & Judge Dredd

As for turn based rpg have you tried child of light? I think it might be Ubisoft only but might be steam too. Not aware of a DRM free version but it was way better than I thought it would be. Lots of fun and nice mechanics.

Darkest Dungeon is another turn based but lots of people do complain about the difficulty. Especially with crimson court DLC. Me I thought it was great and yes hard, bloody hard but fun. Expect to restart several times if your not familiar with the rules before starting. I did but it was a good way to learn too

Broforce: The name turns me off.

Child of Light: I have a strict no-DRM policy when it comes to digital downloads, so that game is not an option.

Darkest Dungeon: I don't like mechanics like permadeath and not allowing you to reload your game if something goes wrong (from what I have tried of Hollow Knight, it seems to suffer a bit of the latter issue as well). I do not like it when a game punishes you harshly for failure; I need to be allowed to fail and not be punished for doing so. (In particular, losing things obtained from before the current playing session (30-45 minutes) is not reasonable by my standards.) I also like to be able to save, try something out, and then reload afterwords. (These sorts of things are why I won't play classic Wizardry (4 excluded here) wthout save states.)

Anyone else have any suggestions? (Preferably one of the three games I listed.)

Not listed, but perhaps "I wanna be the guy"? It's 2D, and sounds like it's in your ballpark. Video here: https://www.youtube.com/watch?v=tnV7cg_3nQE

FEMINAZI: The Triggering

Featuring:

Over 30 different genders, including the ability to create your own!
Minigames
Feminism
Fat
Toxic white masculinity
Refugees
Cultural Marxism
Welfare
Feminism
Burgers and other greasy foods
Wage gap
Mocking the weak
Much triggering
Such oppression
Fat
Evil Patriarchy
Tolerance

Hollow Knight is the most critically acclaimed, but you might look at Dead Cells or Hyper Light Drifter. They have a more pixel look, but offer great 2D gameplay from everything I have read.

Don't get hung up on the name. It's a great game. Have you looked at any gameplay videos for Broforce? If it's not your thing then.........

As for Child of Light, I hope it will end up here one day, I think that you would be surprised how well it plays ;)

I'll 2nd this.

What glitch?

This one:
https://www.youtube.com/watch?v=lPoOdE7TrM0

(You can also get the effects of the old steal duplication trick with a variation of this.)