When you beat the final boss Puzzleman at the end, he will crash and mumble some binary nonsense. But as we all know, numbers like 0 and 1 are always used for secret messages. So to save your time, I transferred the numbles to letters and got a special sentence. (See screenshots Below)







So through a little cracking what we finally got is...
Puzzleman.exe has stopped working.

Considering the heavy meta element of Underhero, this small Easter Egg is just like a fun hint.
That's all. I hope you get some fun reading this small guide.