When Early Access began for this game in July, I'd been waiting almost a year to play it. Its features were heavily limited, it was full of bugs, and it was poorly optimised- all things you'd expect from an Early Access game.
In the following months, the developers have shown that they care about both the game and the community- almost everything has been fixed in weekly patches, features have been implemented at an impressive rate, and a huge amount of our suggestions have been taken on board. For a debut game from a new studio, I'm mightily impressed.
Warmachine: Tactics, as with the tabletop Warmachine, is about clever army construction, positioning, patience, ruthlessness, brutality and keeping your cool. A warcaster defines how his army functions, so the same list can play very differently with the change of a single unit, and there are currently around a dozen units and four warcasters for each faction, so there's a huge amount of customisation possible.
If you've ever lost an evening to a turn-based tactical game, then I can recommend this.
As for downsides? The UI could use a little work and Mac performance is a little wonky, but there's nothing gamebreaking. The learning curve is steep if you've never played Warmachine, but you'll be rewarded if you persevere.
TL; DR: Wizards with guns throw robots at each other. 9/10