Not my favorite meme50 book, but it's a fine book in the end.
His latest tanks are way better and closer to the stuff he draws on his doujins.
Also, apart from those mobile games, he has done the art for two eroges already.
http://www.crg-a.com/work/lina/
https://vndb.org/v6157
And his most recent one.
http://www.pin-point.biz/20_ksrdrk/index.html
https://vndb.org/v16376
That last one is definitely worth. Both OZ and meme50 let themselves go here.