Is this monitor good for 1080p gaming?

Yes. At 24 inches, 1080p looks sharp and is easy to drive, so mid-range graphics cards hit high frame rates. It lacks HDR and adaptive-sync is not listed, so check the refresh rate and sync support before buying for fast shooters.

Does it have built-in speakers or a headphone jack?

No. There is no 3.5 mm audio output and no speakers, so you need speakers or a headset connected to your PC or console.

Can I mount it on an arm or wall?

Yes. It has a VESA mount, and the stand also tilts. Check the VESA pattern and weight limit of your arm before fitting it.

What can I connect to it?

HDMI and DisplayPort 1.2. There is no VGA, DVI, USB-C or Thunderbolt, so older PCs need an adapter and laptops with USB-C only need a dongle.

Is it worth it over a 1440p monitor?

If you want a cheap, compact 1080p screen for a small desk or a second display, yes. If you want sharper text, more workspace or HDR, a 27-inch 1440p panel is the better fit.