I would like to second that recommendation and profess my love for Nex Machina as well.
Easy to learn, but incredibly hard to master. Tight, responsive controls. Fantastic audiovisual presentation that almost never sacrifices readability or frame rate in favor of flashy special effects, which is obviously really important for this type of game.
There is a lot that goes into the optimization aspect of things, such as how to keep the multiplier alive by careful timing of the human pickups. The different weapons are surprisingly varied, each with their little touches and properties that force the player to re-adjust their strategies and priorities.
The best part about this game is probably the stage design. Every area has its own pre-determined flow, secrets and unique enemy encounter design. It's really remarkable how every single stage manages to feel so completely unique while also part of a cohesive whole, if that makes sense.
Like all shmups and twin-stick shooters, it does require a large amount of memorization in order to go for high scores, which can be a bit of a deal-breaker for some people. I once dedicated an entire week to learning and mastering the game, and the incredible sense of satisfaction I felt after pulling off a near-perfect run definitely puts it up there as one of the most memorable experiences I've ever had in video games. I'm sure I've been knocked down the leaderboards by now, but still.
Brilliant game overall. If any of you have any interest in western-developed twin-stick shooters but only have the time to play one, you could do a lot worse than NM.