It's easy to figure out the inspiration behind 20XX. Developer Chris King wanted more Mega Man X and Capcom certainly wasn't listening to fans, so King decided to do it himself. 20XX is a Mega Man X-inspired roguelike that wants to be the game that Mega Man X fans can spend forever with.
"What's better than infinite Mega Man X?" King asked me.
20XX has two-player cooperative play, so I played it on the PAX East showfloor with a random partner. He chose the Mega Man X homage, while I choose the callback character to the sword-wielding Zero. (This was a poor choice on my part, because life was always harder for Zero in the X games.)
The levels in 20XX are all randomly-generated. The game knows where the entrance and exit to a level are located and the general size of a level. It then fills in the rest by taking level makeup (each stage has a different theme and enemy roster) and difficulty into account. You'll see the same mechanics in each level, but the layouts change each time.
20XX isn't easy. Imagine some of the later Mega Man X stages and you'll have an idea of intense platforming I had to go through. Outside the platforming, my partner had can easier time, as their weapon was like the classic Mega Buster, with a regular and charge shot. I had to make due with close-range slashing action.
Over the course of each level, you'll collect currency you can use to purchase power-ups at assorted vendors during and at the end of each level. Finishing off a boss offers both players a brand-new weapon and certain bosses are weak to certain weapons, just like classic Mega Man games. The demo included the villainous hamster wheel Rollster Beta and fiendish fern Death Lotus, both of which I finished off with skill and aplomb. The bosses feel a bit less like Mega Man X's Reploid bosses and more like the larger mid-stage bosses you'd find in the original series, but the familiar "pattern + weaknesses" system applies here..
20XX is a modern roguelike, so there needs to be some form of persistent progression. Here, you'll collect Soul Nuts. Soul Nuts drop occasionally in each level and can be used to unlock additional weapons at the Safehouse hub. Sure, your ability to get through a level is based mostly on your skill, but some extra weapons can make certain encounters much easier.
20XX is pretty good as a Mega Man X fan who's been starved for content. The best part is you don't have to be at PAX to enjoy it; 20XX is already out on Steam Early Access for $11.99. If you're missing a little Mega Man X in your life, Infinite Mega Man X is a damn good bargain.