Hello world with a twist

Perl - 96

(Pretty good, given the theoretical max 97 score)

s{}[Hel0o, w3$=d!];y<"#%&'*.124578:?@BCDEFGIJKLMNOQ/-9>(
    6PRSTUVWXYZ^_`abfghjmqvxz|~\cAk-u)+print

(Note that second line starts with an actual \t tab character)

The code is 98 characters long and contains every ascii char exactly once, plus an extra -.
98 - 2 = 96

There are no string literals here, but removal of any single character breaks the program.

Deobfuscation

There are 3 statements in this program (well, actually 2 but I abused + as some kind of statement separator)

1. s{}[Hel0o, w3$=d!]
   This is a very stretched case of the sed operator. It is more commonly written as s/a/b/, or s:a:b:, but perl allows much more fantasy here: s(a)(b) s(a)^b^ s(a)[b], and even s qaqbq.
   It replaces an empty string (inside {}) with Hel0o w360d! (inside []) ($= interpolates to 60 by default). Because of the lack of an ~= operator, it operates on $_.

2. y<"#%&'*.124578:?@BCDEFGIJKLMNOQ/-9>(\n\t6PRSTUVWXYZ^_`abfghjmqvxz|~\cAk-u)
   This is also a very stretched case, but of a tr operator, which is also called y (y< >( )).
   Let's look at the replacement table:
   " # %&'*.124578:?@BCDEFGIJKLMNOQ /-9
\n\t6PRSTUVWXYZ^_`abfghjmqvxz|~\cA k-u
   I have moved some characters around so that existing string is not broken. The only actually working part here is /-9 -> k-u. It replaces 0 with l, 3 with o, and 6 with r.
   Again because of lack of the ~= operator, it operates on $_
   So now we have the complete phrase in the $_ variable.

3. print
   Lack of arguments makes it print just the $_ variable.

This answer was created before adding of the rule about string literals and does not participate in the contest.

#include <iostream>
int main(){std::cout<<56+"  !$%^&*?12347890-_QWERTYUIOPASDFGJKLZXVBNM,.qypfghjk:zvbHel\x6Co, world!";}

It's completely legit. :P If you remove any character from that string, it will print ello, world!.

CJam, 94

{'H"EJO, WoRLD!"el96A+c/~_-3=0$@}"# 
`&^<>|;:?.()[]\1aBCdfFgGhiIjkKmMnNpPqQrsStTuUvVwxXyYzZ"254b87%*

Try it online! Note that there should be a tabulator right before the linefeed. SE doesn't like tabulators, so you'll have to insert it manually.

• 100 characters long
• repeated alnum: -0 ()
• repeated punctuation: -6 (""")
• repeated other: -0 ()
• repeated whitespace: -0 ()

Total score: 94

I've used the following code to check that none of the characters inside the string can be removed:

"#  
`&^<>|;:?.()[]\1aBCdfFgGhiIjkKmMnNpPqQrsStTuUvVwxXyYzZ"
:A,,{_A\<A@)>+254b87%}%`

It prints an array showing the number of times Hello, world! would get printed if the character corresponding to the index were removed.