San (9)

Hello I'm the strongest! > Then dies first as the (9) girl.

Suwako is zero, because hey Cirno freezes frogs, so she does not like that.

Suwako is similar to Sudoku, all the Cirno sufferings are in numbers, especially committing  Sudoku puzzles.

Suwako can manipulate cursed gods, 9 is a cursed number in Japan.

There are only 9 lifes and 9 continues, through 9 stages/puzzles. Also nine bombs.

9 is also symbol of (9) as in baka, "fool", the 0 as a card arcana, which means Suwako is also a Baka. Everyone is actually.

Bakarat games, are also plenty, just because.

9-ice is a thing, because Cirno is a (9). She might even perfect freeze Allice, but mostly frogs.

Pyonta is the gasmasks of (0). Also the true culprit, that sends morphic resonance field waves to Suwako's brain controlling the game through her, or something like that.

Everyone constantly says (9) in different situations in can mean baka or the number 9.

39 = San kyuu or Thank you, and is also the name of the game. How the game ends is: > "I won't freeze another frog ever again!" (lie) "umm thank you" *hugs*.

The game would run at 999x999pix on 9 different screens, instead just two.

Youseiagnosia is also a thing, that one of the characters might have, because hey.. who doesn't?

Mukyuu, as in there is null kyuu, is the right hand of (0). She is also in love with Allice.

Seiga appears, and leaves, because passing through walls.

Kero sounds like Zero, and the metal rings Suwako is using are actually zeros, not metal rings.

After the climax, Cirno throws the real fool, Pyonta, into the incinerator frozen in a companion ice cube.

There's a roulette puzzle that solution is upside down, because all the numbers added together give 666, and 999 upside down.

Mukyuu is of course is smart in puzzles, or at least tries to be smart. She refers to other girls as rats, and their effectiveness in solving puzzles from 9 to 99, all in multiplies of (9).

All doors are (9), the last door is 0, but it's really a "O".

The ending song is of course triple Baka, because of 39, San Kyuu.

The (9)game, is a series of puzzles in which only those that prove that aren't (9) can win. Of course solving puzzles won't make you smarter, maybe even dumber, so girls still end up being (9)s even after beating the game.

Pyonta Has 2 eyes which represent two zeros, the infinity symbol. What that means might be revealed in the sequel.