There are a few good tower defense titles on the PS4. Defense Grid 2 and Castlestorm are some of the better ones, and Guns Up is cool if you're into free-to-play material. Looking to deepen the pool is The Onion Knights, a port of the mobile game of the same name.

The Onion Knights is set in a period known as the age of gluttony, when war has broken out. Various vegetable-themed kingdoms have fallen to a seemingly unstoppable army. The only one left is the onion kingdom, who has a group of valiant knights and a never-ending stream of cannonballs to stop the horde from cutting them down like the other kingdoms.

This is a simple side-scrolling tower defense title where the castle is on the right while the enemies come in from the left. The basic form of defense comes from a cannon that automatically shoots unlimited cannonballs in a downward arc via a vertical track system. As in any tower defense title, your job is to survive the waves of enemies to win. Losing is accomplished in two ways, but interestingly, none involve direct damage to the castle. Instead, players lose if they either let the cannon lose all health or let enough soldiers reach the castle and form a human ladder to the top and invade.

The enemy forces consist of a variety of foes. Things start off simply with regular foot soldiers and paratroopers, but soon, the enemy forces grow to include dragons, kamikaze birds, and ninjas, just to name a few. That doesn't include boss characters that appear at the end of the given pathway.

To help combat this, your side can also receive upgrades. The most basic comes from gaining enough XP to increase your cannon health and damage and your magic pool, which is used by everything else at your disposal. This includes three other knights who, with the press of a button, can do things like stagger opponents via a ground slam, lay down mines, shoot enemies, or fire homing missiles. You can also call on heroes to help you out for a limited time, though it is odd that the heroes are the same bosses you fight throughout the campaign.

Beyond XP, gold is the real source of upgrading everything in your arsenal. You'll use it to increase your cannon stats and magic point pool. You can also use it to upgrade the abilities of your three other knights and buy items that can have various uses in the field. Only the heroes come with a different upgrade system in the form of hero cards, which can be used in conjunction with gold to upgrade a hero's stats. Earning these hero cards comes from either normal gameplay or through the use of gems, which are earned by reaching specific milestones or completing jigsaw puzzles from pieces earned via normal gameplay.

Combined, this sounds like a tower defense game with some depth. Unfortunately, the truth is that The Onion Knights is far from that description. The endless shooting feels strange on a platform that already has button that lets you choose when to fire. Button prompts are missing in the interface, so you either need to experiment or find an obscure instruction screen if you want to know how to call on anything. Progression for leveling up and progressing through different stages feels like too much of a grind due to the high gold requirements and levels. You're forced to replay old stages multiple times to move on to the next few stages, where you'll have to repeat the process. Most damningly, the game requires no strategy, as your best move is to stay at the top of the screen and fire away to hit every foe before they have a chance to emerge. It can be fun a few times, but it gets boring really quickly.

Outside of the main campaign, there's Endurance mode, which is essentially survival mode; waves are endless and only escalate in difficulty. It seems aimless since there's no high score leaderboard to shoot for, but it's worth visiting quite often. In addition to giving you hero cards once you pass stage milestones, the mode is a great source of gold.

Graphically, it feels like no more attention was given to the game beyond seeing if things work. The textures look fuzzy, and it's especially noticeable when you look at coins pop up from fallen enemies. Projectiles and other particle effects fail to wow, and the static backgrounds look pretty bad, with one lone cloud passing across the landscape again and again. The character designs range from pretty generic to rather dull, with no one looking good enough to merit viewing in the rather meager gallery in the puzzle area. Worse yet are the animations, which are extremely choppy. The mechanic riding around on a goat in the tavern is a good example of how improved animation would've made things look better instead of blurry.

The sound effects all sound muted, and the warning system for incoming fireballs feels completely out of place. The only voice sounds too generic instead of trying to fit with the game's theme. That's probably the biggest complaint that can be levied against the audio. While the visuals are reminiscent of the medieval era, all of the tunes scream lounge music. It also doesn't help that it fades out prematurely and has a terrible sense of looping, so it sounds haphazardly put together.

For a console game, The Onion Knights feels very low budget. The presentation is threadbare from beginning to end, and hardly any effort has been put into creating a consistent theme. The upgrade and progression systems hit snags here and there, but they're fine when compared to the gameplay, which feels like no improvement was made from the mobile iterations. This title makes more sense as a mobile or Vita offering, but on the home console, this is one that can be easily skipped.

Score: 5.0/10