I just picked it up out of curiosity. It's enjoyable, but it's sadly not quite what I was looking for.
The best comparison I can make for it is that it's somewhat close to Into the Breech. You fight waves of enemies with a squad of heroes, except instead of defending spread out city structures, there's only one major one in the center of the map, and all enemies advance towards it. In that regard, it can be pretty fun and a fair challenge to stay alive.
Sadly, I think it has the same "flaw" (In my opinion) that games like Rogue Legacy have--they pride themselves of replayability through their mechanics, but they include things that greatly reduce the difficulty of subsequent runs as you continue to play and die. For example, recruiting additional heroes, something absolutely required to stand a chance at later levels, is locked behind making it to day 5, so naturally you'll progress there on your first run and then wind up dying horribly because you just now have the things you need to continue with. It seems like this is the case for a multitude of various things from structures to equipment, and even each level gets easier as you fail it, which turns the game into a grind for achievements (As those are what unlock your upgrades) rather than something you obtain mastery over as you play. This just makes the early playthroughs frustrating as you're never sure if you failed because of poor tactics or because you just didn't have the equipment the game was balanced around.
Overall, I think the gameplay itself is fun, each piece of equipment imparts specific stats and weapon types have their own unique set of attacks, but you have to prepare to spend some time losing over and over again to stand a fighting chance. I hope an actual hand crafted campaign releases in the future that addresses this, ditch the Orichalcum (upgrade station) for it and go with specifically designed balance instead.