The tower defense genre feels older than it is, with basically only five years under its belt since Desktop Tower Defense and its kin. But its games have seen so many variations to the model and appeared on so many platforms, that it feels very mature in its parameters of game design and implementation. And this is from a genre that has essentially never received a “triple-A” release and most sales come from direct downloads, not on discs or cartridges.

Solo indie developer Cliff Harris of Positech Games is now officially tackling the genre with Gratuitous Tank Battles, a sort of sequel to his popular Gratuitous Space Battles game from 2009. I had a great time playing that game, but didn’t realize at the time that Space Battles, boiled down, really is a tower defense game too. An excellent example on how varied the genre is, even if you don’t realize it.

But Tank Battles is a proper tower defense game with the familiar onslaught of units marching across the screen and grid-based gameplay that veterans of the genre will instantly recognize. It also features an attack mode for most missions letting you experience the other side of combat, and it wouldn’t be a Gratuitous game without an insane amount of unit creation and modification at your fingertips.

I’ll admit right now that I’m not very good at this game. Gratuitous Tank Battles requires a much higher level of concentration, strategy, and skill than your typical tower defense game. Even though the unit paths are already predetermined and mapped out, the types of attackers that flow from the side of the screen are highly dynamic and always trying to take advantage of weaknesses in your defense. And since the bad guys are constantly flowing, you can never rest on your laurels in building and rebuilding your resistance.

Each attacking unit will earn a certain number of victory points upon reaching their destination across your defenses. If the attacker earns enough points, the match is over; if time runs out, the defense wins. Slower units will generally earn more points, but obviously have a smaller chance of actually making it.

But Gratuitous Tank Battles is designed in such a way that sometimes the attacker doesn’t want or need all of their units to make it. Since the attacker is actually fighting back as they move across the field, walking mechs of destruction can take out defense turrets while a troop of soldiers can run in on foot behind them. The mech may very well sacrifice themselves against the cannon and laser fire so the infantry can rain in the victory points. Strategies like this are necessary to win any skirmish in the game.

Certain units are also vulnerable to one type of ammunition or another, so setting out both a varied attack and defense is important. Supplies are constantly refreshing throughout the battle allowing you to replace fallen units, but you always need to consider both what you already have set out and what the enemy currently has deployed before purchasing another unit. It’s a tough balance that strategy fans will welcome.

The game’s graphics feature an overhead view of the battle that’s popular in the genre, but the realistic art style is relatively unique. It’s kind of a curious approach for Positech Games going from the space themed Space Battles to the down to earth look of Tank Battles, but it does make the title stand out amongst the horde of cartoony tower defense games out there.

Honestly my favorite part of the game so far is the sound design. Zoomed out there’s a heavy, march-to-war soundtrack that fits the feel of the game perfectly, but zoom down into the action and the music fades out to give the vast array of sound effects center stage. Every bullet and laser can be heard, mechs stomp on the ground, and infantry scream death rattles. It’s hugely entertaining and highlights how much Cliff Harris cares about the details. If you can spare a moment in this hectic game, take a closer look, and listen, to the action.

Gratuitous Tank Battles is currently in beta, and a pre-order of the game will give you early access, plus a Steam key when the game is officially released.