Hi,

• the title is "lying" to the user, as well as the argument name: you don't use only characters, there are "words" too.
• sample tests are "lying" too, so => missing more representative tests
• this has already been done to exhaustion on codewars. . Meaning it won't pass the beta phase, beeing a duplicate
• no random tests... x/ (you already know about that, tho!)

Cheers