Basically what it looks like, a kinda janky Touhou fangame that heavily pays tribute to the Mega Man X series. I bought this not realizing it was a sequel (I guess the fact that 2 is in the title should've tipped me off), but it doesn't really require that much understanding of what happened in the first game. You're basically Zero in this game, and have to go through several stages with a Classic Touhou Girl at the end to fight. This one specifically pays a lot of tribute to the PS1 entries in the series, using the X5 countdown scenario and X4 title cards for each boss, but just borrows from a lot of different iconic setpieces throughout the series. Like the X PS1entries, it's also pretty brutal in difficulty, with the added effect of the game not controlling very gracefully and bosses that can go on for a long time due to the low amount of damage you can deal. It also doesn't help that I've barely played any of the X series, only knowing what I know of it through watching other people play them because every time I've tried one I've been pretty bad at them. But as someone who's always curious about Touhou fangames, since they can be literally anything, I wanted to give this a try. It's very charming, the group behind it has a clear love of retro games and side scrollers in general, and the art is all fun as well. The main reason I bought this game though is the Steam description for it:

All stage is Rogue-unlike stage. Stage design by human.

Rogue-unlike upgrade system. Anything you get in stage will not lost.

Soul-unlike attack system. It don't have stamina limit. You can attack unlimited times if you like.