Note: this article is based on the original review over at http://www.xboxindiegames.co.uk/
Perhaps unsurprisingly, shoot-em-ups (or shmups) have proved to be popular on XBLIG - with roughly 250 shmups released to date, it's easily the biggest category. Admittedly, roughly half of these are top-down arena shooters following in Geometry Wars footsteps, but there is a reasonable number of traditional vertical/horizontal shmups.
Unfortunately, most of them suck. Many feature fixed patterns of enemies which pay no attention to the player; on a few titles, it's possible to put the controller down, boil the kettle, make a cup of tea and return to find your ship sailing on into the void unscathed. Others feature clumsy controls, limited vertical visibility (a major issue on modern 16:9 displays), odd weapon layouts or just generally low-quality gameplay. However, there is the odd game which stands out, and Revenge of the Evil Aliens is one such title...
In truth, Revenge of the Evil Aliens is exactly the sort of game I was hoping would appear on XBLIG. A tongue-in-cheek homage to B-movies, sci-fi and mod-90's shmups, ROTEA sticks the player into a spaceship and points them in the direction of a large horde of aliens who look to have been more than a little inspired by Mars Attacks!.
Gameplay-wise, ROTEA offers a mix of the three traditional shmup genres: your ship is controlled via twin-sticks in the usual arena-shooter way, but the battlefields alternate between horizontal and vertical scrolling. Also, ROTEA implements a fairly unique power-up system - enemies may drop power-up icons in the time-honoured fashion, but these don't work in the usual way. Instead, the first time you pick up a given icon, it enables an RPG-style levelling system: kill enough enemies and the given attribute (shot range, power, shields, etc) is boosted. Pick up a second icon of the same colour and a modifier is added to the attribute - for instance, making bullets more powerful or making the shield spin quicker. However, you can only level up one attribute at a time: picking up another colour means you start to boost that attribute instead.
It's a novel but slightly clumsy system: the low-level enemies which drop these icons are randomly generated and placed: you have to take what you're given, which can often be absolutely nothing. This problem is further compounded by the fact that you lose all of your powerups when you die and your initial ship is amazingly underpowered: starting again mid-level is often equivalent to David taking on Goliath armed with a slightly damp sponge. Fortunately (except on Hard), you're given infinite lifes, but for some sections - the "jumping bugs and giant UFOs" area on the second level springs to mind - you're probably better off just quitting and starting again.
The game also offers another relatively unique feature: up to four players can take on the aliens in cooperative play and the game mentions a "link-up" system which appears to allow you to join all four ships together. Admittedly, it's not something I've been able to investigate, but it's an interesting idea!
Moving onto the audio-visual experience, and this is where ROTEA shines. From the backdrops to the UFOs, giant brains and the various other enemy entities, the graphics are beautifully rendered. The only sprite to let the side down in any way is your ship: it's essentially a square with a blob on each corner. It's certainly a functional way to render a spaceship with omnidirectional movement and firepower, but something prettier would have been nice! The rest of the graphics do make up for this however, in conjunction with the 16-bit style soundtrack and the B-movie plot which unfolds as you conquer each level.
The level design can be a bit hit-and-miss, especially on the first level: this starts with several waves of identical UFOs heading towards you. While this offers a challenge, it's also a bit repetitive and could put newcomers off. Thankfully, the game also includes several set-pieces per level: the UFOs are followed by an giant rock and an asteroid belt, which in turn is followed by a bizarre Asteroids mini-game, where the asteroids are... giant floating brains which explode in a shower of blood. Obviously. There's several similar double-take moments throughout the game, but the first is also the best!
Overall, there's a wealth of slightly cheesy gameplay to be found here, and this slots in perfectly with the B-movie look and feel which ROTEA manages to pull off so well. The three levels which make up the core gameplay are somewhat on the short side, but there's a host of unlockable mini-games and a secret fourth level, for those determined enough to take on the challenge of the Hard and/or Insane difficulty levels. The game also features it's own award system, thereby giving players both a glimpse of what can be unlocked and a target to aim for.
Much like the B-movies ROTEA seeks to emulate, it's not a AAA-rated blockbuster, but neither does it aspire to be. Instead, it's cheap, cheerful and cheesy, making it nigh-on perfect for XBIG. As such, I'm happy to recommend it: for all the glitches and flaws, this is exactly the sort of thing we need to see more of!