If the remakes of Nintendo's Metroid: Samus Returns for the 3DS and the Switch port of Donkey Kong: Tropical Freeze are any indication, it's that side-scrollers are still very much loved. Indie games that take inspiration from the classics like Shovel Knight, Dead Cells, and Ori and the Blind Forest, remind us that side-scrollers can never go out of style as long as little bit of innovation is applied.
Here's my list of games that deserve side-scroller comebacks:
One of the most aggressive games out ever. Enemies with ridiculous hit boxes jump from left and right. They hurdle, fly, and walk over you from every direction. All you can do is spam your attack button and run like hell. In this game, you get decent platforming while being able to scale walls and grab onto some ledges, which was quite innovative back then. Most importantly, it had its own identity. It may look like Castlevania, but it has ninjas and robots in them. More modern versions of Ninja Gaiden were bland rip-offs of Devil May Cry and God of War. Its identity whisked away and has been suffering from mediocre reviews. A walk back in the park with a modern side-scroller remake with more fluid controls, more detailed Lovecraftian horror-styled enemies, and more power ups should re-re-invent the series and jumpstart love for it again.
The early Castlevania games weren't really very good. But they were both interesting and challenging to cater a following. It wasn't really until Symphony of the Night where the series truly, really, absolutely shined. It is a feat that had been somewhat replicated in Aria of Sorrow, Dawn of Sorrow, and Order of Ecclesia. Then the PlayStation 2 and 3 titles sunk in, all of them sucked, being mediocre rip-offs of Devil May Cry. Now because of Konami's series of blunders, it's the fans who have to suffer. If they want to stay safe, they could produce a Castlevania game similar to Symphony but broader and with a Belmont as one of the main characters. (We want more than one!) Konami should really consider this while Netflix's Castlevania is really hot right now. To fight off the Castlevania itch, I recommend Dead Cells by Motion Twin, which can be purchased from Steam.
Demon's Crest is one of the hardest but most innovative side-scroller of its time. It follows the story of a gargoyle named Firebrand and his quest to collect the six Crests. Each crest contains unique powers, and once he collects them all, he would have the power to rule the entire Demon Realm. Sounds familiar. In any case, as Firebrand you can fly, shoot fireballs, and cling to walls. When you obtain a new Crest, Firebrand can transform into a different gargoyle with new abilities, allowing him to explore new areas in the map. It's like Metroid, only grimdark.
This game was loads of fun until it started to intentionally make you rage quit. There are so many things happening in the game that it's hard to keep up. If you include other issues, like stupid hit boxes and sluggish controls, Kid Icarus can be a challenging game with really nice platforming.
Ice Climber is actually a "Vertical Scroller" since you're tasked to climb a mountain. With two trendy games about climbing mountains, Celeste and Getting Over It, it makes a bit of sense to see a more casual and friendly game about reaching the summit. There's lots of platforming, a bit of action, and killer penguins. With the right difficulty this game sounds like a blast. Besides, the Ice Climber characters are no stranger, especially to Nintendo fans as they make an appearance in Super Smash Bros.