Actually just spent the last 5 or so hours with it. It's probably bundle fodder but looking at it, thought it would scratch an itch I had at that particular moment, and it did.
It's a little bit Chuzzle a little bit Puzzle Quest but much more manic than either. The game is essentially grinding away in the dungeon until you build up enough gold/wood/stone to continue your upgrades and get further in. Long before I finished upgrading my armor I had a run that came up with 9.7 million so I figured it should be a cakewalk to finish at that point, but I still haven't managed to get the 10 million needed to finish the game. The end game is very much a matter of just getting a lucky run plus a good board which can end up being mildly frustrating but it really doesn't get in the way of the addictiveness.
That's the thing with it, since each run only lasts a couple minutes, there's a very strong "One more run" aspect which can easily make the hours disappear on you. You're always just a couple runs away from the next upgrade, and once you've finished all your upgrades, it's just one more try to finish the game.
It will probably show up in a bundle at some point, but if it looks like something you want to play right now, I'd say it's worth it for the price. Gave me a solid day's entertainment so far, and I still need to settle in and get that final run to clear the game at some point.