This pretty much nails the whole situation.
The process of getting it running is much more rewarding than the final state of actually running it.

This thread just inspired me to try Flare [1] on my N900 (OC'ed to 900MHz) under Easy Debian. Flare might not be a full Diablo2 replacement, but I guess it deserves an honorable mention.

If I turn all the performance settings down, then performance-wise it seems to be borderline playable, which is great. It mainly runs fluently, but every now and then there's a small pause of maybe half a second. However, I only tried the very first screens of the game, where not more is happening than a few little goblins hopping around.
I have no idea what later happens in caves crawling with antlions hurling fireballs and frost flashes, and I'm not at all eager to find out, because the controls are a nightmare. Efficiently navigating with the N900's cursor keys (qwerty keypad) is impossible, which makes maneuvering via mouse/touchscreen almost mandatory. Customizing controls is possible but a little cryptic in Flare, and you absolutely need to have Esc mapped to your keyboard, otherwise you won't be able to gracefully close the game from fullscreen.

I also remember having played boswars years ago on my N900, which was fast enough, but even there the controls were awkward.


[1] https://packages.debian.org/jessie/flare