Haven't beaten Remilia yet since the update wasn't out but it was super good and reminded me well of Castlevania-like fangames I've played so that's something.
My Old Steam review in beta:
All Right, I have not played Touhou,I have not really played Castlevania(just the nes one a few times),and I've BARELY played Metroid or even know what happens in It even though i should BUT This all changed because of this upcoming game and it's demo.
I had been eyeing on this game for a while looking from the pack that Angels Of Death is in and I was intrigued by it because o knews what Touhou was and had a maid that can stop time like a certain yellow vampire we all know and love :^) and to see that we're gonna get a game that has a time stop mechanic and is going to be a Metroidvania? We'll sign me up OH and look it's on sale, would you look at that hmmmm...Honestly, I'm glad i didnt buy it during that time because i want the full price to go toward toward the Devs to make a great game i can play anyday.It's already gor overwhelming praise just from it's Early Build and has great hour of play time already. This is promising and I hope and expect, great and more

PS- I wrote this a while ago but couldnt post it cus wifi crashed and luckily copied it so I could post It, I am hype for this thing lol

Full review on my website: https://www.nepikigaming.com/reviews/touhou-luna-nights/

''It’s probably a good moment to bring up the question I asked earlier: can outsiders that are not familiar with Touhou enjoy Luna Nights? While that’s hard for me to say as I am a Touhou fan, I’m of the opinion that it’s a very solid Metroidvania that anyone should be able to enjoy. You could say that it’s a budget Metroidvania to an extend with how short it is and how much it ”borrows” from other Metroidvania’s, but the developers executed it pretty well regardless and that’s what matters most. The castle is fun to explore, there are a ton of secrets but most of all: controlling Sakuya Izayoi is an absolute joy. It is a decently difficult game with stats that barely increase over the course of the game, yet encourages risky play to recover HP and MP. Stopping time is a great mechanic to use and balanced since it’s on a cooldown–at least, for most of the game. It is true that you unlock an ability that breaks the game later on but eh, that is pretty late-game and it’s very much optional. I’ve had a good time mastering the game and especially the fun boss battles, and therefore my recommendation is to beat and complete it!''

Un muy buen metroidvania, las mecanicas de control del tiempo lo hacen atractivo y el control del personaje se hace gratificante con el snail time junto al stop time. La historia es inexistente pero no la necesitas para disfrutar el juego aunque es lo que mas eché en falta. Muy corto, lo justo para que puedas hacerte a todas las mecanicas, lo cual en mi opinión es otro de sus aciertos, ya que justo al final sentí que se estaba quedado seco el juego. Muy recomendado para jugartelo cuando te entre el mono de un metroidvania.

The best metroidvania I've played yet. Incredible music and visuals, absolutely love the graze and magic system, love the stop time mechanics, the different ways you can use your knives and weapons and how that combines with the time mechanics and oh my god the BOSSES. The boss rush in this game is easily the most fun I've had in any game with a boss rush.

EDIT 2/9/21: Played through this again for the Cirno boss fight they added. It's just as good as all the other fights, though I wish it was in the game when I first played it because with the amount of times I've played it wasn't as much of a challenge as I would like, but still incredibly fun. Anyway, this game still rocks and has some of my favorite bosses in any 2d game.

first metroidvania i played as both a beginner and a recent touhou fan, my opinions on this are: this game is SO GOOD. not only you play as sakuya, one of the most badass characters in touhou, but you use manipulate time as well and there's so much you can do with it; this game has one of the best mechanics of all time i've played with. The sprite work and animations are great as well--I love how everything moves! I wished the game was a bit longer and they adjusted some stuff about the game, like how you get the sprint ability right near the end, but the rest feels fine. Nice that touhou fangame community are still making some quality gems. I love you ladybug for making this.

copied from steam review posted on 7/17/20

This game is NUTS. I've wanted to get into Touhou for a while, and although this is a spin-off, it's one of the most enjoyable and fascinating games that I've ever played.
This is a super sick metroidvania where you can stop and slow down time, with knives being your main weapon. The soundtrack, level and boss design, and combat all work beautifully together to create an amazing game. It's got its fair share of challenge throughout the campaign, as well as with a very welcome boss rush mode that you unlock after completing said campaign.
THL has such fluid movement and its some of, if not the most fun I have ever had just moving around within a game. This is an absolute must-play.

Mechanically excellent but would've vastly benefitted from being a traditional platformer rather than a Metroidvania. Areas never connect to each other in any interesting or meaningful ways and half the upgrades are literal keys to locked doors (this happens five times and that's not even counting the upgrades that aren't keys but may as well be like the screw knives and the ice magatama), greatly diluting the exploration--the hidden upgrades help, but they only do so much.

The time stopping is fantastic and the game's existence is worth it for that alone, it's an idea that never gets old and the way it interacts with all the other systems is genius. It's put to many creative uses, but this is further reasoning for why I don't think the Metroidvania structure benefits it much. If the level design had been more focused I think even more mileage could've been squeezed out of this system since it could've justified more complex challenges in every room as you wouldn't be needing to backtrack through them multiple times. Both Guacamelee titles come to mind as games that are kind of open but regularly funnel you through linear gauntlets of platforming challenges that push your moveset to its absolute limit in an incredibly satisfying way that I think could've worked great for Luna Nights too.

In its current state it's difficult for me to not feel that Luna Nights has some major missed potential, but that shouldn't take away from the fact that the rest of it is still solid and contains a lot of clever systems that connect to each other in engaging ways. It's worth a playthrough, but it makes me sad thinking about what it could've been and how close Team Ladybug was to creating a masterpiece.

also the extra stage kind of sucks

A combination of bullet-hell and metroidvania, TouHou Luna Nights is a fast-paced thrill ride with bangin tunes and challenging bossfights, all wrapped up into a nice, concise 5-6 hours of total playtime.
Whereas I'm not very keen on pixel-art indie titles (especially those with an anime theme), this one broke the mold by having a really slick and fluid animation style that made the game fun to look at.
The story wasn't amazing by any stretch, but it was at least intriguing, and the dialogue was quite charming. The focus obviously lies on the gameplay, which was handled very well.
Like a classic metroivania, you start off with little abilities aside from basic movement, a jump, and your basic attack (throwing daggers). As you explore and progress throughout the map, you find more abilites that allow you to progress even further and become more powerful.
Combat is tight and precise, and the integration of time stop/slow mechanics in combination with both the combat and the platforming made overcoming obstacles really rewarding. Regaining MP, HP, and Time was fun too as it involved needing to "graze" incoming attacks (narrowly dodge).
Some gripes include the inability to look up/down, making some platforming challenges a bit of a gamble if you weren't already familiar with them. This game also includes enemies who can move and attack through walls, which is a pet peeve of mine, especially when they aren't ghosts or something that makes sense, and they just don't have hitboxes that collide with walls. In my opinion, those kinds of enemies are just artificial difficulty and lazy enemy design. Additionally, I felt the difficulty of some rooms was cheap and lazy as well, being packed with enemies who target you directly alongside little fireballs that can dodge your attacks, so that by the time you get through a certain room, it feels like luck more than skill.
All of this considered, this would've been a 3-star were it not for the awesome bossfights. Those weren't lazy at all, and were super fun to fight, especially once you got into the rhythm.
Overall, a fun little game that you can probably beat in a weekend if you're a seasoned gamer with experience in either bullet-hell or metroidvanias, or just titles that are known to be difficult. This game would be hard to get into for a newcomer, as the entry bar is pretty high in terms of difficulty.
I recommend.

Although I have zero interest in the Touhou brand, I found Luna Nights to be quite enjoyable. A more "bite-size" Metroidvania experience that melds together gameplay mechanics from several different franchises, which then creates its own original concept.

Touhou Luna Nights is a rather fun experience, though its steep difficulty curves through bullet-hell mechanics prove tiresome in extended play sessions.

This niche combination of genres, as well as its central narrative, make it rather hard to recommend to the average Joe Schmoe, yet it is certainly worth a go if you're a fan of either Metroidvania or bullet-hell games. Touhou Luna Nights is additionally on Game Pass on console, so if you're already subscribed to it, you have nothing to lose.