Can you actually play modern games on these monitors, is that even possible? I'm curious what they'd look like.
Erm, no. That's a 15.75Khz monitor. You'd need at least VGA (30Khz) to play modern games.
As for what they would look like (on VGA). I believe that modern games on a good 21"+ CRT screen would look awesome, the downside is the amount of desk size you'd lose
Resolution would obviously not be very high - probably something like 1280x1024, more if you got a really good screen so you'd obviously not have a particularly big viewpoint, but I think the quality of the picture would be pretty fine. My father was a TV engineer so I grew up around stuff in his workshop and IMO, we're only just now seeing picture quality that rivals where good CRTs were at when they stopped being produced. We're finally getting there with good LED / OLED and 4K stuff. With the earlier "HD" screens, even at a premium price point they weren't a patch on good CRTs.
All that being said, I do like my super-wide 21:9
If you really want a blast from the past, go and find someone with a vector screen (think Asteroids, Tempest, Star Wars). They were somewhere around 1024x512 (I forget exactly) back when the rest of the world was on 320x200. Such a great shame they got a bad rep on reliability because it would be mind boggling where we might be with them had they not died off so quickly. Aside from the screen though, another problem was the amount of compute power required to push the ever expanding number of lines about the screen. Same problem as today basically, just 30+ years ago.
Anyway, enough rambling...