Redeeming the Archos 28 somewhat is its use of Android 2.2 (aka Froyo), which although no longer the latest version of the OS is still nicely up to date. Balancing out that positive, though, is the removal of the official Android Marketplace app store. In order to get applications on the Archos 28 you'll either need to install then manually, or use a third party store such as the aptly named AppsLib applications library.
As you might expect, apps are just as restricted by the small screen as video playback. But more critically, the Archos 28 just doesn't have the horsepower to cope with anything intensive - even trying to play back Flash videos via the browser caused it to crash, and games such as Angry Birds had similar issues, bringing the system to its knees. Basic web browsing, Twittering, Facebooking and emailing are possible, although again the low-resolution display means you wouldn't do so as a matter of course.
Audio playback had no major issues, at least. Format support is as comprehensive as could be asked of a player in this class - MP3, AAC, OGG and even FLAC all playable. We'd question the wisdom of anyone cramming lossless files on a 4GB-capacity player that really won't make good use of them anyway.
Unsurprisingly the bundled earphones are pretty much trash, proving both uncomfortable and reproducing music in a way we can most kindly describe as 'uninspiring' (and accurately call woeful).
Plug in a respectable pair of third party 'phones and the situation improves. The Archos 28 isn't the best sounding media player in the world, but most listeners will find it good-enough. The overall tone is fairly warm but muddied, and lacking in clarity - if you use a really good pair of earphones you'll definitely wish you'd purchased a more capable player.
The Archos 28 isn't a bad media player (or Internet Tablet, to use Archos's nomenclature), but it doesn't do anything amazingly well. Its audio quality is pretty average, the low resolution resistive touchscreen display isn't the best interface for a device this size, and although Android is a theoretically feature-rich OS, it doesn't run especially well on a media player of this size.