Recommended by PKMudkipz as part of this list.

The Mega Man franchise is something I've held dear to me as a fan of classic no-frills side-scrolling run-n-gun action, but despite the plentiful spinoffs into nearly every genre under the sun, I've never actually ventured very far into any of the franchise's numerous spinoff series. So, at the behest of one user's suggestion, I'm dipping my toes into yet another Mega Man spin-off series with Mega Man Zero.

Taking place in the far, far future, Zero (from the Mega Man X series) has been revived by a struggling Reploid rebellion force to help aid in the fight against an X that has gone from all-loving hero to genocidal despot. Already, the concept of turning your old hero into the villain of a spinoff is novel, and transforming the dynamic from law-enforcement agent snuffing an attempted rebellion in Mega Man X to rebel fighter struggling against a powerful government agency is something MMZ runs with at full speed. MMZ is no doubt about it, the hardest Mega Man Game I've ever played. Your resources are incredibly limited, the enemies you face are tough as nails and are always placed in a way to wreck an unsuspecting player's shit, and the way missions are structured means running out of continues can lock you out of content and chances to get additional resources. This constant struggle against the game's many challenges really sells the struggle the characters deal with, and makes you feel like every victory is earned by the skin of your teeth. Despite this, I can't say it ever dips into outright unfair territory. If you're patient and pay attention to your surroundings and enemy attack patterns, the game can quickly become a breeze, especially with the breadth of weapon options and the ease with which Zero controls, sliding and wall-jumping everywhere while never feeling slippery or loose.

MMZ, while fun and challenging, suffers from a lot of systems that feel superfluous. The Cyber-Elf system is very helpful for newcomers and skill-impaired players, offering many boons that can help take the edge off the game's difficulty, but it feels a bit like an afterthought and the amount of resource grinding required to make the most out of some of them feels like a waste of time. There's a ranking system that encourages replays and mastery, but it's incredibly demanding, knocking off points for many, many actions in a way that discourages using a lot of the tools the game offers a player, and it's pretty frivolous even if you do care about that kinda thing, as there's no immediate reward for getting S-Ranks outside of bragging rights. But as a whole, Mega Man Zero was a solid time. It wasn't enough to immediately sell me on the rest of the entries in this sub-franchise, but it's a solid action-platformer and a good dose of Mega Man X-flavored action if you still need that particular itch scratched and (somehow) haven't tried this spinoff series out yet.