This is probably the best twinstick shooter I've had the opportunity to enjoy, it gets about as close to Treasure (as in the game dev, see Ikaruga, Gunstar Heroes etc) without being Treasure to me but without falling into the one pitfall they've not really managed to avoid in most of their game
The core mechanic here is the time limit, which can be replenished through an item that is dropped every so often by enemies (the internal system in charge of that is fair and even biased toward letting you succeed, so long as you kill stuff close to you at a decent pace you'll get more than enough time to handle things)
Another thing that I do like is (almost) no randomness, everything that happens is in direct reaction to your own actions, what seems random isn't and with little efforts can be understood to a degree where you can get it to give you the outcome you want (the hard part being juggling that with all the other simple mechanics that also make the game)
Though I will recommend the game overall it really depends what you enjoy and how you approach this type of game.

If you're sort of a content tourist / one and done kind of player the game is gonna be rather short (2-4 hours depending on how much you're struggling, the game at a low level of skill really gives you every opportunity to win without really going into ♥♥♥♥♥♥♥♥ territory as "death" is but an inconvenience and the timer is loose enough that if you're doing what the game asks of you you're not gonna have an issue with it besides a couple places (you can basically win by facetanking everything in all levels but 1), though there lies the only problem in this game for a casual player, in my opinion the game asks little of you until the second to last level and there if you don't git gud the game is gonna whoop your ass thoroughly,.
Different playable characters do offer you the opportunity to find one that you feel good playing with

If you're the type to perfect a game, the game practically has no ceiling and gives you tools to helps you make that easier, wanna git gud nice and easy? game has a rank system and gives you a way to keep track (or automatically reset for you) if you're not eligible for the best rank anymore once you've perfected a level (and the games tracks that for each characters as well), not enough to quench your thirst for challenges? you then have a boss rush, then an arena wave mode (it's not really endless just long), then there's scoring with a system that's theoretically very simple (2 or more enemies killed within a certain window of each other give 50% more points and the faster you complete a level the more extra points you get) so in theory it's just about killing stuff fast and in groups, in practice considering the ambient chaos it's very hard to actually consciously do it but once you do results show immediately and unlike many games that almost immediately fall into the "it has to be perfect to be a good score" once you start scratching the surface this one still leaves you the opportunity to have variation in how a great score is achieved and I can confidently say that despite having over 3.5k hours in that game I'm not even sure there's more than a couple levels I truly fully understand to a degree where I could confidently say "yeah that's how you get a perfect score here", and the few times I thought I did someone ended up proving me wrong, you could easily spend hundreds of hours on a single level and still have someone come and beat you through a slightly different approach you hadn't considered till now, and it's not a matter of the game being random because it really isn't, doing more or less the same thing will have more or less the same results but it's chaotic enough that it's not exactly the same over and over again.
The one small issue I have with higher skill level stuff is that there's a snowballing effect where sometimes doing a tiny bit better can result in massive improvements overall, and inversely a small mistake early in a long level can definitely kill any chance of a good outcome

tl;dr: handcrafted twinstick shooter with absurdly low skill floor but equally absurdly high skill ceiling