Perl 5, 64 bytes

.1;";1.
\"Hi, Retina!->";$_=<>;chop;print y///c>5&&reverse
eq$_;

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Satisfies:

2. The first character is a ..
3. It contains an e.
4. Its length is even.
5. Its length is a perfect square.
6. It contains an a.
7. It contains a > character.
8. Contains the exact string ->.
9. Contains the exact string Hi, Retina!.
10. The sum of the first two Unicode code points is a multiple of 5.
11. The 10-th character is a ".
12. The last non-empty line does not have any duplicate characters.
13. The first line is a palindrome of length > 5.

Summary for future answers:

• First character is a ..
• Its length is an even perfect square.
• Contains the exact sequence ->.
• Contains the exact string Hi, Retina!.
• The second character's Unicode code point, mod 5, is 4.
• The 10th character is a ".
• The last non-empty line does not have any duplicate characters.
• The first line is a palindrome of length > 5 (in characters).

Verification Ruby script

13. Perl 5, 64 bytes

.1;";1.
\"Hi, Retina!->";$_=<>;chop;print y///c>5&&reverse
eq$_;

Try it online!

Satisfies:

2. The first character is a ..
3. It contains an e.
4. Its length is even.
5. Its length is a perfect square.
6. It contains an a.
7. It contains a > character.
8. Contains the exact string ->.
9. Contains the exact string Hi, Retina!.
10. The sum of the first two Unicode code points is a multiple of 5.
11. The 10-th character is a ".
12. The last non-empty line does not have any duplicate characters.
13. The first line is a palindrome of length > 5.

Summary for future answers:

• First character is a ..
• Its length is an even perfect square.
• Contains the exact sequence ->.
• Contains the exact string Hi, Retina!.
• The second character's Unicode code point, mod 5, is 4.
• The 10th character is a ".
• The last non-empty line does not have any duplicate characters.
• The first line is a palindrome of length > 5 (in characters).

Verification Ruby script

Perl 5, 64 bytes

.1;";1.
\"Hi, Retina!->";$_=<>;chop;print y///c>5&&reverse
eq$_;

Try it online!

Satisfies:

2. The first character is a ..
3. It contains an e.
4. Its length is even.
5. Its length is a perfect square.
6. It contains an a.
7. It contains a > character.
8. Contains the exact string ->.
9. Contains the exact string Hi, Retina!.
10. The sum of the first two Unicode code points is a multiple of 5.
11. The 10-th character is a ".
12. The last non-empty line does not have any duplicate characters.
13. The first line is a palindrome of length > 5.

Summary for future answers:

• First character is a ..
• Its length is an even perfect square.
• Contains the exact sequence ->.
• Contains the exact string Hi, Retina!.
• The second character's Unicode code point, mod 5, is 4.
• The 10th character is a ".
• The last non-empty line does not have any duplicate characters.
• The first line is a palindrome of length > 5.

Perl 5, 64 bytes

.1;";1.
\"Hi, Retina!->";$_=<>;chop;print y///c>5&&reverse
eq$_;

Try it online!

Satisfies:

2. The first character is a ..
3. It contains an e.
4. Its length is even.
5. Its length is a perfect square.
6. It contains an a.
7. It contains a > character.
8. Contains the exact string ->.
9. Contains the exact string Hi, Retina!.
10. The sum of the first two Unicode code points is a multiple of 5.
11. The 10-th character is a ".
12. The last non-empty line does not have any duplicate characters.
13. The first line is a palindrome of length > 5.

Summary for future answers:

• First character is a ..
• Its length is an even perfect square.
• Contains the exact sequence ->.
• Contains the exact string Hi, Retina!.
• The second character's Unicode code point, mod 5, is 4.
• The 10th character is a ".
• The last non-empty line does not have any duplicate characters.
• The first line is a palindrome of length > 5 (in characters).

Verification Ruby script

13. Perl 5, 64 bytes

.1;";1.
Hi, Retina!->";$_=<>;chop;print y///c>5&&reverse eq$_;
#

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Satisfies:

2. The first character is a ..
3. It contains an e.
4. Its length is even.
5. Its length is a perfect square.
6. It contains an a.
7. It contains a > character.
8. Contains the exact string ->.
9. Contains the exact string Hi, Retina!.
10. The sum of the first two Unicode code points is a multiple of 5.
11. The 10-th character is a ".
12. The last non-empty line does not have any duplicate characters.
13. The first line is a palindrome of length > 5.

Summary for future answers:

• First character is a ..
• Its length is an even perfect square.
• Contains the exact sequence ->.
• Contains the exact string Hi, Retina!.
• The second character's Unicode code point, mod 5, is 4.
• The 10th character is a ".
• The last non-empty line does not have any duplicate characters.
• The first line is a palindrome of length > 5.

Perl 5, 64 bytes

.1;";1.
\"Hi, Retina!->";$_=<>;chop;print y///c>5&&reverse
eq$_;

Try it online!

Satisfies:

2. The first character is a ..
3. It contains an e.
4. Its length is even.
5. Its length is a perfect square.
6. It contains an a.
7. It contains a > character.
8. Contains the exact string ->.
9. Contains the exact string Hi, Retina!.
10. The sum of the first two Unicode code points is a multiple of 5.
11. The 10-th character is a ".
12. The last non-empty line does not have any duplicate characters.
13. The first line is a palindrome of length > 5.

Summary for future answers:

• First character is a ..
• Its length is an even perfect square.
• Contains the exact sequence ->.
• Contains the exact string Hi, Retina!.
• The second character's Unicode code point, mod 5, is 4.
• The 10th character is a ".
• The last non-empty line does not have any duplicate characters.
• The first line is a palindrome of length > 5.