Excubitor is one of the more clever takes on old-school, top-down shooting we’ve seen in some time. After a few minutes with the game, its mix of classic arcade-style gameplay with modern tower defense mechanics seems so logical, you’ll wonder why there haven’t been more attempts at this cross-genre combination.

Across four planets and over a dozen levels, players must pilot their upgradeable Hammerhead ship to hold back waves of drones, protect their mothership, and build up defenses. Similar to games like Kingdom Rush or Defense Grid 2, the giant maps feature numerous spots for building a variety of towers. As in a standard tower-defense game, Excubitor gives you a moment at the beginning of each level to lay down your defenses and then (usually) a short period of rest between waves to build more towers, upgrade current towers, or dismantle unneeded structures.

The difference between this and the average tower-defense game is you control your ship directly at all times. You can’t rely entirely on automated weapons, especially when the action heats up; there’s a frenetic pace to the game that frequently requires you to be in two or three places at once. This is especially important to remember when it comes to the Antares–your mothership. While the Hammerhead can be regenerated if it gets destroyed, once the Antares is destroyed, it’s game over.

There are plenty of layers of strategy to manage in Excubitor, and they keep you on the edge of your seat. Building up defenses around the Antares is almost always the top priority since it can be quickly overwhelmed if you aren’t paying attention. Having to focus on defense creates a welcome and different feel compared to traditional 2D shooters, where you simply scroll forward while destroying everything you can. With nine distinct types of towers to build, there’s ample room for experimentation to see what weapons work best for any given situation.

These towers range from anti-air missiles and machine-gun batteries to EMP pulses that slow ships down, and even a powerful laser weapon that bounces from enemy to enemy. Building anything requires power, however, which can be problematic. You’ll start each level with a certain amount of construction energy, and you can earn more by building a generator. But you have to sacrifice space typically reserved for turrets to do so. Balancing your defense with the need for more power is a constant battle, lending Excubitor a spare, but effective bit of resource management.

Maps also contain elements that can potentially help stem the tide of overwhelming enemy forces. Levels often feature environmental hazards and traps like huge fuel tanks that can be destroyed to create a circle of fiery death, mine-throwing plants to help beat a giant boss, and other interactive tools of destruction. It’s a nice addition to the game that allows for consistently satisfying destruction.

But Hammerhead remains your best weapon through the game. This spunky little ship can be upgraded from top to bottom and supports a variety of weapons systems. There are 17 in all, many of which are unlocked over time. The ship has two weapons slots to outfit with disparate items Standard machine guns and rockets are effective standbys, while the shotgun-like weapon provides a satisfying sense of power at close range. The more sci-fi weapons, like the multi-targeting Tesla coil, feel ripped straight out of classic shooters like Raiden. Flame and ice throwers are a creative touch that let you simultaneously freeze and fry when both are equipped, which is terrific fun if only for short-range use. Your ship can be upgraded to be tougher, faster, and more offensively effective as well, and all weapons can be further enhanced with three or four tiers of upgradeable options.

Levels are also packed full of goodies to find. Every destroyed drone and building provides the currency necessary to buy and upgrade new weapons between levels, and there are specific caches that can be activated for other bonuses. Many of these bonus stores require you to hold your position for a period of time, so there’s a trade-off between focusing on your primary objective and sticking it out for more collectables.

Levels are designed to force players into risk/reward situations, where frequently crossing from one end of the map to the other is a necessity. Backtracking isn’t tedious because there’s enough exploration and action in each level that it feels almost like a roller-coaster ride. Certain objectives might be in one corner of the map, while the Antares is on the opposite side and potential riches can be scattered anywhere in between–all while multiple waves of enemies are approaching.

These planet excursions each end with a boss battle–nail-biting events that require the precise use of towers, environmental traps, and speed. Since you’re simultaneously trying to destroy a giant mechanized terror and keep the Antares alive, boss battles feel like wars of attrition. You’ll constantly be trying to whittle down the boss spacecraft’s defenses, wait for its weak spot to appear, and damage it. There’s also the added complexity of rushing around to rebuild destroyed defenses and, most importantly, keep the mobs of drones from overwhelming the Antares. Even on the normal difficulty setting, these boss levels are trying, frantic exercises, but beating them is immensely satisfying.

Fast action and strategy define Excubitor, and the smartly-designed levels and customization options encourage experimentation with the different weapon load-outs. Excubitor is a great action game that deftly mixes two distinct genres into one great new flavor.