I think, copyright line would be fine only for TSRE map overlay (or maybe not - yellow text does not allow even this use).
But everything else (image saves, terrtex textures) is not allowed.
https://developers.g....com/maps/terms
Quote
10.5 Intellectual Property Restrictions.
No distribution or sale except as permitted under the Terms. You will not distribute, sell, or otherwise make any part of the Service available to third parties except as permitted by these Terms.
No derivative works. You will not modify or create a derivative work based on any Content unless expressly permitted to do so under these Terms. For example, the following are prohibited: (i) creating server-side modification of map tiles; (ii) stitching multiple static map images together to display a map that is larger than permitted in the Maps APIs Documentation; or (iii) tracing or copying the copyrightable elements of Google’s maps or building outlines and creating a new work, such as a new mapping or navigation dataset.
No use of Content outside the Service. You will not use any Content outside of the Service except as expressly permitted to do so in Subsection (d). For example, you will not export or save the Content to a third party’s platform or service.
No caching or storage. You will not pre-fetch, cache, index, or store any Content to be used outside the Service, except that you may store limited amounts of Content solely for the purpose of improving the performance of your Maps API Implementation due to network latency (and not for the purpose of preventing Google from accurately tracking usage), and only if such storage:
is temporary (and in no event more than 30 calendar days);
is secure;
does not manipulate or aggregate any part of the Content or Service; and
does not modify attribution in any way.
No mass downloading. You will not use the Service in a manner that gives you or a third party access to mass downloads or bulk feeds of any Content. For example, you are not permitted to offer a batch geocoding service that uses Content contained in the Maps API(s).
No incorporating Google software into other software. You will not incorporate any software provided as part of the Service into other software.
No removing, obscuring, or altering terms of service, links, or proprietary rights notices. You will not:
remove, obscure, or alter any Google terms of service or any links to or notices of those terms, or any copyright, trademark, or other proprietary rights notices; or
falsify or delete any author attributions, legal notices, or other labels of the origin or source of material.
So, in free fun project you can use google maps, but for any kind of payware route I wouldn't even touch it.