"You ever think about life? Like what it all means, and what your purpose in it is?" could be questions that start a conversation similar to this book.

On the bright side, the topic of the meaning of life was nicely discussed by our main character, even if some of the touched upon "life philosophy" was a bit mundane and obvious. The character development and the conclusions that were going to be drawn were predictable, but that doesn't mean that they were less true or less important conclusions. The book feels fuzzy and warm, and especially when he talks about his memories, you feel a sort of comfort.

Besides the semi-philosophical parts though, this book has quite some issues. Firstly, it reads weirdly, especially at the beginning (probably a translation issue), and the conversations with the devil are strangely "anime-like", trying to put the specific anime-humor into written form. The comedy parts in it just weren't for me.
Far bigger problems posed basic continuity issues. I get that this book is about the individual, so the focus should not be on society and the world in general, but somehow making certain very important items (

like clocks or phones

) disappear for everyone has zero consequences on everyday life. No chaos whatsoever. If it doesn't even seem to bother people if things suddenly disappear one morning, why even make it (as the author) so the thing disappears for everyone? Just say that it will become invisible/unusable/untouchable for the individual who makes the deal and you won't have that major plot hole about the world appearing unchanged after

f*cking CLOCKS

have vanished. Then, why does the main character not try to make actual useless things disappear? The devil ultimately decides, yes, but he doesn't even try. Obviously the plot wouldn't work this way because no one actually ponders over the question if making an automatic apple peeler disappear is worth it to extend your life. Still, to avoid this issue as the author, you could have just made the rule different. "Only important things". Or "only things everyone uses" or something like that. Furthermore, the main character is very reluctant about making things disappear for everyone. It seems he does not understand at all the extent of his responsibility. "One day of my life and no one can ever eat chocolate again? Yeah whatever go ahead."

The DEVIL has to talk him out of it because he considers it too big of a waste!

This is also incredibly selfish. He made

movies, phones and clocks

vanish. Not only do people cherish these things deeply, there are entire businesses built on them, without them, entire systems collapse, but not only does this seemingly not happen, but the narrator doesn't even consider it! He just thinks "it will be fine, whatever, they'll get over it, a day more of my life is more important." Excuse me? Also there are some other logic errors (e.g.

they're talking about phone calls after phones have disappeared

). 
I understand that all of this is to ensure the narrator is properly philosophizing about life and his place in it and its meaning, and not busy thinking about the consequences of his actions for the people around him, and since the point of the novel is to discuss the meaning of life, you could just look over these plot issues. I guess it's a matter of personal preference.

In summary, it's a great, short read for when you feel generally a bit lost in life and need some comfort and some things to ponder on. It's not a great piece of literature in my eyes, but nonetheless an enjoyable book.