20XX wears its influences on its sleeve. If you're familiar with Mega Man X, then slipping into the metallic bodies of 20XX's two core protagonists--the gunner Nina and the swordsman Ace--will feel like coming home again. Both characters are satisfying to control, and executing combinations of dashes, wall jumps, and attacks is an intuitive process with lots of room for in-depth choreography.
But the levels you tackle are where 20XX differs from its inspiration, with obstacles and enemies procedurally strung together. For the most part, this works as intended, with new enemies and hazards progressively introduced with each new stage. A corridor that is usually calm might be riddled with spike traps the next time you enter it, adding new challenges to a previously safe area. Other times the shift can feel unfair, filling the screen with projectiles and moving parts that demand superhuman reflexes with practically no margin of error. These areas can bring the strongest of runs to a grinding halt through no fault of your own, which is incredibly frustrating.
Dying is central to progression in 20XX though, so even the most infuriating of deaths have silver linings. During each run you'll accrue Soul Chips, a currency used in 20XX's hub world to purchase permanent upgrades, item unlocks, and single-use buffs. Simple additions to your overall health and special weapon energy are priceless during more difficult later stages, while simple perks such as enemies dropping more health or buffs to overall dash speeds provide welcome twists to the gameplay loop you quickly become familiar with.
Additional weapons are also available and are acquired in the same fashion as Mega Man titles: ripped straight from the husks of bosses you defeat. Each boss battle features a central mechanic; a giant mechanical face will employ an impenetrable shield for brief moments during a battle in between flurries of projectile attacks, while a sentient Venus flytrap will lob mortars at you from afar. These and many more abilities can be picked up after each successful victory, or tossed aside for additional life, energy, or run-specific currencies. 20XX forces you to consider what equipment to take and which to leave behind, but it rarely engages you in scenarios where these choices are truly tested.
The very same boss fights are a prime example of this failure. A handful of them provide complex strategies for you to overcome, combining a good mix of precise platforming and attack timing to make victories hard fought and rewarding. Others make good use of the rooms they take place in, providing you with alternative means of attack such as exploding platforms that fall after you touch them. But far too many rely on cheap tricks and uninteresting attack loops. The less egregious of these just feel boring, while the worst unsettle the balance of mechanics to a point where you're forced to just accept taking damage in a hurried attempt to finish your foe off as quickly as possible. And with the randomness of potential upgrades strewn across levels thrown into the mix, having a compelling boss fight is a rare occurrence.
Despite this, it's hard not to get sucked into taking on multiple runs of 20XX's campaign in the hopes of reaching its conclusion. Each individual run is brief enough to make it a perfect match for a portable console such as the Switch, filling in odd gaps of free time with exciting randomized challenges. Daily and Weekly challenges with their own leaderboards are more competitively focused without shaking up the core loop, aside from giving you access to items you might not have unlocked yet for a useful little test drive. The boss rush mode is equally enticing, despite the inconsistencies with their designs. This mode offers a good way of familiarizing yourself with their mechanics without being caught off-guard during a strong run.
20XX isn't just a solo experience, giving you the ability to tackle its campaign with an online partner in tow. Collectible currencies are shared between each player while upgrades are duplicated, presenting you with some opportunities for decision-making but never forcing you into a corner with one player being clearly more valuable than the other. Cooperative play is slightly more chaotic, but having both ranged- and melee-focused characters in a single stage does inject the action with more life, despite the difficulty and complexity of enemies seemingly remaining equal.
Procedural generation is sometimes lambasted as a cheap alternative to intricate level design, and 20XX doesn't always do enough to break that stereotype. But despite its inconsistent level make-ups and underwhelming boss designs, 20XX is still an engrossing side-scroller that perfects the feeling of navigating dangerous, pitfall and enemy-filled stages. Nostalgic itches are sometimes tough to scratch with modern reincarnations of older formulas, but 20XX is a satisfying iteration on a fan-favorite formula. Even if the results are mixed, it's easy to appreciate a Mega Man-styled adventure that never has to end.