A consistently highly fun experience, which is rare for a VN of this length. I was mindblown by every route. The main character, heroines and antagonists are all good or great across the board, which is also rare for a VN. The soundtrack and art are very much "early 2000s VN vibes", in a good way.

This is basically essential reading if you're really into chuunige, given the fact that it is believed that this served as inspiration for Fate and Dies irae. Whether you're into other Nitroplus stuff like Muramasa, Light, Type-Moon or mecha, I would recommend it. It is pretty underrepresented in the western VN fanbase, especially considering that other 2000s VNs are usually the most popular and acclaimed ones. Unfortunately the sequel is literally unplayable except Windows XP, and even then it sometimes doesn't work.

Somehow, Voltage made this, and it's delightful. It had me laughing through my tears more than once.
I was surprised by the overall quality of even if TEMPEST, and that was even before really getting into the story.
The developers don't allow the game to be boring for even a moment through the main story (OK, maybe a moment in one of the later routes). The game played me, and I loved it. I felt like I was on a rollercoaster the whole way through (I did feel the ride slow down in the last bits, though). It doesn't shy away from tragedy. I don't think I've ever been so invested in the successes and failures/losses of a character as I have been in Anastasia's. Anastasia is a fantastic protagonist (and ~gorgeous~). I genuinely really like the other main characters too. UGH just let them be happy.
I liked the romance OK, but I would say it's not one of this game's greatest strengths. I love romance, but it's not really what I was here for. The game didn't need it, basically.

The character sprites, and especially their facial expressions, are superb. So many great, freaky expressions. The CGs are generally really good too.
The logic in the trials isn't anything very challenging, but I still thought they were fun. If playing without a walkthrough, the investigations preceding the trials might take some trial and error (pun not intended).
I think the route structure is clever, for a game with multiple paths and love interests.
I enjoyed watching even the plot twists that I predicted play out.
I feel that even many games that I like don't mind wasting my time, but such is not the case for even if TEMPEST (aside from the poor Skip function, which I'll mention shortly).

I enjoyed this so much that these issues don't really touch it, but I will note them anyway (along with more praise, naturally).
Background noise tracks of crowd chatter and such generally either loop very poorly, or last all of five seconds before ceasing, which can be distracting. The sound in the game is otherwise great. The music is fantastic. I wish I could buy the soundtrack! The instrumentation is gorgeous (and they are legitimate instruments played by legitimate artists where applicable — not synthesized as is common in other games. The emotion and flavor of these sounds are very real).
The voice work is super. The game is fully voiced, with the exception of the protagonist, which is such a shame for a character with this much of a personality. And it's disappointing that such a strong character as Anastasia lacks character portraits. These two would be the things I was most disappointed about.
The translation is quite good. There are more than a few typos here and there. The sort of things you could miss if you aren't scrutinizing.
I wish that more thought had been put into the text "skip" function. It's really slow, and can't be adjusted in any way beyond skipping read text or skipping all text, making it pretty troublesome to double back for other route endings. It took me out of the flow of the story more than it should have. I didn't want to miss any content, but the experience of the game would likely be better if I didn't bother. The regular route endings are where it's at. (Edit: I have seen someone else's Skip function in action, and it's much faster than mine is. No idea why. You might get lucky with your copy/system. Or not.)
Skipping to the next choice is becoming a more common feature in otome games, and I missed it here.
The game did crash on me once, which isn't something I recall experiencing with any other Switch games. Not a big deal if one saves often. (Edit: the game of the aforementioned "someone" also crashed a heck of a lot!)

This is really all of my complaints, and I can't even complain... I'm really looking forward to the fan disk. I hope Voltage will make more games like this one.