First of all, I did not like how the characters controlled compared to the earlier X games.
The stages are either meh or complete ass. Dynasty, Inferno and Primrose especially stood out as very bad stages.
One stage that I did find cool however, was the elevator level.
Because of these stages I really appreciated the Retry chips.
I liked the many upgrades that were available with chips. However, it also meant that in order to be effective you would have to focus on one character because you get nowhere close enough chips to upgrade all three characters a reasonable amount.
The beginning is a little rough but as soon as you get armor the game becomes extremely easy. The Icarus body armor especially trivializes the game.
As for the bosses, they were alright. I found most of them somewhat interesting and unique.
Although, the final boss did kill me twice with some bullshit. First time he pushed me off the platform which was an instant kill and then in his last phase he just has an instant kill attack? Fucking stupid.