I've recently put some work into a port of OpenXcom for the RG350m, an inexpensive handheld console that runs linux. It's got a nice little milled aluminum case, a 480p screen, and really nice buttons. Most of the work that I've done on the port has boiled down to tweaking some stuff around the idiosyncrasies of the OS & hardware and then implementing some support for the analog sticks for controlling the cursor and battlescape camera. Performance is pretty good and the controls are at a point where I'm comfortably playing through a campaign right now with few complaints.
You can download a release and judge my code quality over on my github repo (uncletrunks/OpenXcom-od). I've got a work in progress port of OXCE coming along as well and I'm anticipating having that up to par with the mainline port relatively soon.