Ninja Gaiden has a 2d game, what platform? And Dusk is an FPS, no?

35 years of games disproves OP

Also OP needs to git gud and play Shadow Warrior on NES (without cheating)

At its better moments, Odin Sphere's combat system is fantastic (Leifthrasir has two surprisingly different combat modes for each of the 5 playable characters), but the level design is poor and repetitive.

An Odin Sphere with lighter emphasis on combos and a solid Metroidvania map would be crazy good.

I liked Prince of Persia: The lost crown. The combat system was slightly more complex than your usual 2d scroller and the boss fights were quite challenging.

Does The Subspace Emissary counts?

Because it's by far one of the best side-scrolling beat'em ups I ever played.

Strider

Strider 2

Strider (2014)

Dragon's Crown

Muramasa

Odin Sphere

Ninja Gaiden

Guardian Heroes

A bunch of beat em ups from the 90s up to now.

A SHIT TON of 16-bit era games is great. A bunch of great ones on Saturn/PS1 Not meant as an insult OP but I have noticed your tastes are pretty limited. You need to widen your palate.

I disagree with the notion that games with simple fundamental actions can't have an engaging or strategic flow. But otherwise you're probably right that most melee side scrolling are rather simple when it comes to your number of actions, and rely more on movement and timing. In a sense, Soulsborne games are similar. Souls movesets are shallow compared to say Devil May Cry.

Vanillaware games like Odin Sphere Leifthrasir might be what you're looking for. Check out its free playable demo.

Oh don't let the Soulsborne hardcore hear you say that. Soulsborne can be completed with one button yeah but they got more complex over time, Elden Ring is rather quite complex in movesets, there's combos and all but nothing as deep as DMC indeed. DMC has the same problem though, as did OG GOD of war, you can get through the latter on normal difficulty with square square triangle and you can get fairly far into DMC4 with just simple triangle combos and the odd square, it's the difficulty getting higher that makes combos necessary and 2d just can't bring that. Even if these games do end up having combos at some point, I can't see how they'd be used instead of simply going in tap, tap and getting out of the way. Fighting games are obviously very complex so I don't even understand what I'm actually complaining about here, to be rightly honest. 

I'll give Odin Sphere a whirl, it's on PS plus catalogue I think. Cheers for the recommendation.

It's important to note that Leifthrasir is a 2 in 1 pack. The original PS2 mode (Classic) and an updated mode (Refined). Their combat systems feel VERY different.

"Classic" has a stamina bar, different moves with different rhythm and animations. "Refined" is more action-based (but the difficulty goes up as you progress, so it isn't as button-mashy as it may appear early on).

Most people seem to prefer Refined because it's smoother and less punishing, maybe there are more reasons I'm unaware of. I only learned about how different the two modes are after finishing Gwendylon's path on Refined and trying Classic. Classic's "clunky" combat is more up my alley because I'm a sucker for weighty combat with limited action. But I didn't bother replaying the whole game.

My advice is that if you find yourself enjoying the game, try finishing the first stage on both modes and see what works better for you.

Will do. I'll probably enjoy the updated controls I'd reckon.