I got it working on my A43... had to edit /etc/permissions/handheld_core_hardware.xml and add the line:
<feature name="android.hardware.screen.landscape" />
Then tried downloading Wesnoth again, and it installed.
This requires root access of course... I'm using UrukDroid which makes that easier. Hopefully the same can be done with the stock firmware too.
FYI, I figured this out by installing aLogcat... when the install failed earlier due to a missing feature, it printed out what that feature was in the log.