I will not censor all of these achievement icons, so fair warning to those who don't want to get spoiled/exposed to them.

All of these are achieved by doing a (semi) casual playthrough of Stages 1-6

Anomaly Detected
Open the Game.


Stand by Me
Complete the Tutorial. If you skip out on it the first time you can replay it in the practice stage menu.

Breaking Dawn
Clear the game on any difficulty without using a continue. This is easier on Mokou since she has multiple free continues that don't count as continues.

Flawless Performance
Complete stages 1-6 without losing a life, Deathbombing/Having the barrier break do NOT count as losing a life.

Mystery of Eternal Night
Do the same as Breaking Dawn except with each playable character.

These are achievements specific to mostly stages 2-3.

Rupert's Tear
Kill the Snake Eyes (Umbrella) during the ribbon attack in stage 2.


Speed Demon!!
Don't get hit during the high speed section of Stage 3 (the part where you get a barrier from your partner).

Cicada Shell!
Manually break your barrier before getting mochi'd for Trap "Dangerous Road to Okinoshima". The timing on it is a little tight but you can try it over and over again in spell practice.

To unlock EX/EX-U you have to 1CC the main game (AKA don't use any continues and clear stages 1-6). Normal mode clear unlocks EX while Hard/Lunatic unlock EX-U.

Close Encounter of the Third Kind
Clear the EX or the EX-U stage with any character.


Marisa's Encyclopedia of Magic
You'll get this for free after beating the EX stage.


Composed Victory
Same as Flawless Performance, except because you do not have your partner deathbomb timing is a little tighter.

Return to the Old Order
Clear EX or EX-U with each character. Do note that beating 1-6 with one character unlocks their partner to be able to do this stage. If you have Mystery of Eternal Night already then you can just get this quickly.

Compiling them both here as they're the new gimmicks introduced to the game.

Nightmare Awakening
Survive long enough where your Rampage state wears off.


Berserker Crew
Enter the Rampage State 18 times in one run. You can force a rampage state by pressing C while you're currently in a frenzy.

Immortal Sacrifice
Run into the boss while you have your frenzy up, this'll proc your Immortal Sacrifice.


I Can't Die Yet!
Die even more times to proc Phoenix Rebirth from Mokou.


HAPPY BIRTHDAY!!
Using only the Immortal Strike, end someone's spell card. You cannot shoot the boss or use a bomb to damage them or else that'll fail the achievement. I did this by simply placing Mokou on top of Wriggle while she was doing the Glow Light "Shimmer Fireworks" spell card.

Shivas FR below in the comments said "the easiest way i've done this one was by going into the spell practice, I picked easy difficulty. Of course you need to choose Mokou as character. Then take the Stage 3 and choose Leap Sign "Swifty Rabbit Crossing". In that training just stay close to the mochi beam to fill up the suika lantern and then in frenzy mode, kamikaze yourself straight on the boss. You need to do it 3 times in total to kill it".

All of these have to do with "Collecting" a spell card. To do so you just have to no-hit/no-bomb/no-breaking the barrier the spell card. Forcing a Berserk state to clear the card faster will still let you collect it, as long as you avoid damage/bombing of any kind. All spell cards have to be collected by one character, and all of them can be collected in spell practice.

Blessing of Immortality
Collect the final spell card on stage 6 Finale "Bless the Resonance of Moon and Heaven" as any character.

Spell Card Collector
Collect all spell cards from stages 1-6 on any difficulty. Again, these can be collected in spell practice once you've had the first run through the game, and all of them have to be collected on only 1 character.

"RKD-EK9"
Collect EX/EX-U's final spell card "The Last Days Apocalypse" as any character.


Unthinkable Spell Cards
Same as Spell Card Collector but with the EX/EX-U stage.

That's everything in the game currently achievement wise.

Happy Hunting.