Hmm, I really like the concept, and when the game works it feels great, but it did feel quite rough in some aspects that I wish were fixed up.
As said, for the most part, the game is pretty neat. The graphics and presentation is quite bland and simple, but the act of slashing through multiple enemy attackers in slow-mo and watching your shadow replay is very exciting and slick when you pull it off. Some aspects like the fact that your shadow is your actual hitbox is strange at first, but it works to the game's benefit because it forces you to tackle every single enemy that is attacking you in a combo, which is the ideal scenario that should be pushed. Indeed, some of my favorite levels were the ones where you just face a bunch of opponents and have to deal with them in an almost puzzle-like manner, slashing all of them without hitting one a second time since it would force you out of the combo.
The big issue for me was dealing with enemies that have a lot of health on them, like elites or bosses, as when it came to them, it put the breaks on the gameplay way too harshly and it became so boring. Whenever you hit an enemy with multiple hitpoints, it makes it so that they block your second attack no matter what. Because of this, it's best that you just strike them once and then wait, since if you attack again, they block and you are punished and need to wait to recover stamina. But it's just so annoying, since the game, by activating slow-mo and everything after the first strike, is practically screaming at you to take another swing! But no, the best thing to do is wait, waiting for the slow-mo to end and then waiting for the enemy to attack again: so much waiting! Would love it if there was some risky way to keep the offense going through skillful play: for example, maybe when you hit them, you can choose to wait it out if you want to play it safe, or you can look at what direction they are getting ready to block in and try to attack from the opposing direction: if you do it fast enough you can keep the combo going and it will keep looping like that, whereas if you don't they will block and you need to scramble to get your stamina back. If there was something like this, you could also have some kind of cool Sekiro-esque combat going!