Cubically 6x6x6, 14 bytes, cracked by H.PWiz

[+1[+7]35@]100

Per this meta post, Cubically with the -6 flag counts as a completely different language (Cubically 6x6x6) than with the -5 flag (Cubically 5x5x5), which is again different from the default language (Cubically 3x3x3).

Cubically 6x6x6 does not have its own wrapper on TIO (i.e. there is no tio.run/#cubically-6x6x6), but the language itself is on TIO; it simply requires the -6 flag. I believe this is valid due to the linked meta post and the fact that the language is on TIO, but simply needs more to run than just one of the /srv/wrappers scripts.

Dennis' 8cc answer acts similarly; the language is on TIO, but it requires multiple commands and command-line flags, none of which were specified in the answer.

Cubically 6×6×6, 14 bytes, cracked by H.PWiz

[+1[+7]35@]100

Per this meta post, Cubically with the -6 flag counts as a completely different language (Cubically 6x6x6) than with the -5 flag (Cubically 5x5x5), which is again different from the default language (Cubically 3x3x3).

Cubically 6x6x6 does not have its own wrapper on TIO (i.e. there is no tio.run/#cubically-6x6x6), but the language itself is on TIO; it simply requires the -6 flag. I believe this is valid due to the linked meta post and the fact that the language is on TIO, but simply needs more to run than just one of the /srv/wrappers scripts.

Dennis' 8cc answer acts similarly; the language is on TIO, but it requires multiple commands and command-line flags, none of which were specified in the answer.

???, 14 bytes

[+1[+7]35@]100

Oh huh, this is still uncracked!

Cubically 6x6x6, 14 bytes, cracked by H.PWiz

[+1[+7]35@]100

Per this meta post, Cubically with the -6 flag counts as a completely different language (Cubically 6x6x6) than with the -5 flag (Cubically 5x5x5), which is again different from the default language (Cubically 3x3x3).

Cubically 6x6x6 does not have its own wrapper on TIO (i.e. there is no tio.run/#cubically-6x6x6), but the language itself is on TIO; it simply requires the -6 flag. I believe this is valid due to the linked meta post and the fact that the language is on TIO, but simply needs more to run than just one of the /srv/wrappers scripts.

Dennis' 8cc answer acts similarly; the language is on TIO, but it requires multiple commands and command-line flags, none of which were specified in the answer.

???, 14 bytes

[+1[+7]35@]100

Watch someone crack this in 6 seconds...

???, 14 bytes

[+1[+7]35@]100

Oh huh, this is still uncracked!