I've been hooked on playing DotAGE since this weekend. It's a cute base builder and it's really compelling. It's very easy to get stuck in the loop of "just one more turn" and playing for way too long, which is nice (as long as you actually do remember to take breaks).
Also, the demo is very good! It took me about an hour to play and it showed off the game nicely while still paring down the game to make a simple first look experience. There's also a DLC expansion but I haven't tried that out yet.