Have a look at Paper Sorcerer, Elminage Gothic and Darkest Dungeon, all available here.

I find battle chess a good tea and bicks pal... be aware that people will want to HELP you play however

Battle Chess is an RPG now? Who knew? =P

well its what I play at work but rpg (very pretty) and windows mode would be ghost of a tail

Have you taken a look at the DROD games? They are more puzzlers with light RPG elements similar to Desktop Dungeons, but might fit the bill. DROD 4: Gunthro and the Epic Blunder is intended as a good starting point to the series for beginners. DROD 1+2+3 is also a good option and provides a lot of content.

Get Fire Emblem Heroes on mobile (assuming you have an Android phone), it's not quite as deep as the real thing but for a F2P mobile game it's pretty good. It's been eating most of my spare time since releasing on Monday...

Of course now I want to spend £70 on the set of Fire Emblem Fates to get a proper FE experience... Damn addictive games.

As for actual PC games, Shadowrun does seem a good fit, maybe Banner Saga too (though that's a bit more involving and may not work for the shorter play times to your looking for, can't remember if you can save during combat either or if it has a windowed mode)

I've yet to play it but Blackguards might fit the bill, or Kyn. Can't remember the exact name now but the Conquistadors game is a turn based RPG, though I found it a bit lacking myself.

Well, don't expect to play a bad-ass fighter, or a bad-ass assassin, or a bad-ass anything, really. The game is unforgiving, and thus goes contrary to most of our RPGs reflexes.

For example, your professionnal, experienced assassin is cornered in a dark alley by two armed thugs, mercenary-types. In most RPGs, it sounds like a classic early-game combat to spice things up, right? Well, in AoD, you'll want to flee, because seriously, facing off 2 muggers on their home turf is stupid.

In my game, I chose the assassin carreer. I put most of my points on "killing stuff", "killing stuff by surprise" and "lying my ass off so that I can kill stuff by surprise", which sounds cool, but means that I have an "hybrid" build, and that I suck at pretty much anything. I can maybe lie my way past a drunken guard, use my reputation to bully a random scholar, or fight off 2 beggars (3 if I can knife one of them by surprise). And most of the missions I can take now (I'm at the end of chapter one) set me against groups of 4-6 trained, armored fighters led by suspicious and vigilant leaders.

So I have now 2 options : Be a very polite, very meek assassin who gets the city guards to do the dirty work for him, or be a dead assassin.

So yeah, that game is HARD

But fun, though. You'll die often, but the designers aknowleged that by giving you colorfull death descriptions to read before you reload your save ^^

Lionheart lets you save at any time, so maybe that? You can even save during dialogue cutscenes where control is taken away from you, weirdly enough. The game itself isn't anything particularly special, but at least you can play knowing that you can quit it on a dime without losing progress.

The Fates games aren't proper Fire Emblem experiences any more than Heroes is. They're more gimmicky experiments that didn't quite pan out. And Conquest and Revelation have some of the dumbest stories you'll see in gaming, which is to say nothing of their million other problems. Like the fact that you have to buy even more DLC if you want to actually know important character back stories that were cut out of all three games to sell back to players.

(But then, I'm one of those older FE fans who consider Fates to be the game/s that burned the series to the ground and desecrated its corpse, so your mileage may vary.)

I'd say Awakening is my favourite FE game, so I assume I will enjoy them (I'm not all that bothered about the story anyway) but thanks for the heads up. It's a shame they went all in on DLC but I enjoyed Awakening without ever buying any DLC for it so I doubt I'll be too bothered (particularly as I'll have three campaigns to play through if I buy the whole package)

The game isn't really that difficult if you stick to an archetype (fighter or talker) and focus on a few skills, at least in your first playthroughs. I've finished it several times and I'm not some super-gamer who's willing to invest hundreds of hours until he gets a game's system.
The game has flaws, e.g. some skills are useless, could have more quests etc. But the basic concept is really great imo. It's also quite short and offers a lot of replayability due to many different plot branches and playstyles, so it could be just right for a lunchbreak.
Maybe try the demo and see if it's interesting.