Good story and gameplay overall, RPG system and combat are somewhat lacking, though
Personally, I've always enjoyed doing detective work in RPGs. This brings back memories of certain great quests in BG II, Witcher, etc. The same must go for the authors of this game, because basically it's just one big investigation. And this indeed makes for an engaging gameplay. Searching for evidence, interrogating witnesses, etc. is a lot of fun. This is helped by good writing and dialogue. Shadowrun relies on writing a lot: besides dialogue there are colorful descriptions of scenes and about each and every character you meet. These are interesting to read (and contain a lot of lore from Shadowrun universe) and really help with game immersion. There are also light roleplaying puzzles. They aren't too hard, but figuring them out is lots of fun.
So on the story end the game does really good. I cannot say quite the same about the core RPG system and combat, though.
The system somewhat lacks in depth and variety. It's enough to keep things interesting for one playthrough, but I wouldn't be compelled to play more just to try other character builds, etc.
As for combat, I liked using cover and some battles were really good. But then, in a lot of encounters enemies just ran up to my group and were quickly put down. Which is to say, AI leaves something to be desired.
My other complaint is that on "combat" levels you have to move your group in turn-based all the time, and this can get a little bit tedious. I think the game may have benefited from transitioning in and out of turn-based on running into enemies (like in Fallout 1-2).
I should also mention Shadowrun's limited checkpoint save system. This wasn't a huge issue for me. Actually I found this to eliminate any compulsive saving and reloading (what would happen if I choose another dialogue option and so forth). But on one occasion this did bite me in the ass. I was unhappy with my dialogue choice and decided to replay. And was I punished for this momentarily weakness. It turned out I had to replay a whole lot more than I thought. After replaying (which was actually totally unneeded) I decided to sell my old armor and buy a shiny new one. But apparently doing it all in one transaction was too much to ask of the game. It bugged and I was faced with a wonderful choice: to replay again or spend the rest of the game running naked. After replaying again I first sold the old armor and then bought another in a separate transaction. Well this was wrong, turned out you aren't supposed to sell the old armor first. How about replaying for the FOURTH time? For the record: replaying a level 4 times to explore the intricacies of the game's bugs is not fun, not at all.
Overall (and nevermind the rant earlier) if you like RPGs and good story in games, you should play Shadowrun Returns. The RPG mechanics and combat are fine for a single playthrough, but not much more than that.