The story is a bit tongue in cheek. It is light-hearted dark humor. The protagonist is supposed to be super-weak but is over-powered. The story is originally by author Tsuyoshi Fujitaka and has been translated into English through Jnovel. It is a young adult novel and has elements that would appeal to the boys in the age group especially if all of the gore was brought to the anime screen. However, there are some interesting scenarios in the dungeon and the resulting outcomes demonstrate keen forethought and an interesting plot device.
I do think the character - a mimic is a little one-dimensional. I was expecting something a little more developed like the Royal Mimic described in the "Disciple of the Lich" series. I may go on to read volume 2 simply to find out if the Mimic develops their mimicry skill further and whether they are truly evil or good. The character could go either way.