I pulled back the astroturf today and the situation under the ugly astroturf was just gross. Lots of old and chipped glue.
I scraped up some of glue and a lot of it came off after only a couple minutes of work. I think I'll buy a better scraper and maybe rent a wire brush grinder and see where we sit.
I've been looking into different types of concrete filler/resurfacing products and it looks like getting a cheap and easy-to-mix bag of thin set is a good way to go. I'm not necessarily after a perfectly new floor, just something a little cleaner and more smooth... because I have a little floor painting idea that I just can't get out of my brain...