With the wife and boys out of town for a few nights, I took one afternoon to see what I could make in 4 hours. I was really pleased with aspects of the language and libraries that, compared to my language of trade (C/C++), enabled me to add features almost as quickly as I could think of them. A+ would use again, especially if they could figure out mobile platforms.
For mobile, take a look at Moai[1]. I don't like it as much as LÖVE -- it feels more low-level and fiddly to me --but it's Lua and it's pretty full-featured.
I work on Moai - we just shipped 1.0 last week. It's designed to be a minimalist, open source framework for game development. We think that's the best approach for experienced game devs - look at Bungie's Crimson Steam Pirates on iOS and Chrome for an example of what you can achieve. If you need a higher level scene manager, then check out Rapa Nui for Moai at https://github.com/ymobe/rapanui
If you want to write mobile (outdoor) games using Lua, take a look at my site http://geolua.com/
It allows you to write (multiplayer) games that execute in the Browser. Lua is executed on the server side. The browser side is implemented in GWT and is getting pushed the game state.
It really is too bad that they still don't have anything for iOS/Android. I used Love a fair bit a couple of years ago and I seem to recall a few people who had been able to get it working on iOS, it doesn't look like anything came of it though.
