In general, for physics students there is no need to read the whole book and only the above chapters are needed for all practical purposes at undergraduate level. In particular, one at least need to learn Group Action. Chapter 1-3 are the most essential introduction, while chapter 4,5,7,8 are for completeness.
The style is rather informal and hence should be accessible to many first readers. However, for some reason I did not find it very 'accessible'; indeed there are abundant examples to look through and tons of exercises to work with, some of them extremely useful to cement understanding. However, for unknown reasons (which I suspect to be just a matter of compatibility of style of the user and the author), I do not find his explanations enlightening, nor the informal discussion particularly explanatory of some difficult concepts. For example, factor groups are well written here but I do not find it comfortable enough to understand it fully. I do agree on the fact that his examples help very well.
Therefore this review was read up to chapter 3 only up to group action. I will come back again for the exercises/review or if there is a need to visit other chapters such as groups in topology.