We like the logo it looks very professional but it doesn't portrait the image of a fun company with monster innovation and enthusiasm. We would suggest you to revise the logo a bit and add some fun aspects to it.
I can see from your other additional design that you try to make it more fun but I think the little guy is maybe a bit too much. It's neat which is good, but I'm wondering if we can make it more fun but still keep the neatness. Thanks :)
Also you may play around with the logo and not worry about the wording "monster co., ltd." This might give you more freedom in designing a stand alone logo. Thanks.