From Star Castle to Star Citadel

Funny thing about Star Castle: it’s a classic. An amazingly fun game. Yet it’s rarely mentioned in videogame histories, and even when it is, it's usually only briefly. This is pretty unbelievable when you consider it provided the inspiration for Yars’ Revenge, one of the most enduringly popular Atari 2600 games of all time - but more on that later.

In Star Castle you control a ship with which you attempt to destroy a large central cannon, or gun turret in the centre of that screen. Sounds straightforward enough, but the cannon is protected by three layers of shield rings, each made up of twelve segments. Each segment takes a couple of shots to destroy and, if you destroy all the segments in a ring, the cannon regenerates a whole new ring.

The player's ship attacking the cannon and destroying its defensive shield rings in the arcade version of Star Castle.
Figure 1. Playing the Star Castle arcade game: at the beginning of a level the player's ship goes in for a strafing run against the cannon's defensive shield rings.

As if this weren’t enough, the cannon is protected by three defensive homing mines. These guys will chase you down and destroy you, and you don’t get any points for shooting them.

The cannon's defensive mines try to chase down the player's ship.
Figure 2. The cannon has deployed its defensive mines, which are chasing the player down the screen. Fortunately, on the earlier levels anyway, you can move faster than the mines can. Not so much later on though.

Even if you can shoot your way through the shield rings and avoid the mines, if the cannon gets a clear shot at you, it will fire a powerful and fast-moving ball of energy in your direction that will instantly fry your ship upon the slightest contact.

A narrow escape for the player as the cannon just misses with its return fire.
Figure 3. Something of a close shave for the player here. The cannon has returned fire at the player through a gap in its shields. On this occasion the player manages to just about dodge out of the way. Maybe next time they won't be so lucky.

Worse still, the longer you play, the faster the game gets: the cannon rotates faster, meaning it takes less time to aim at you accurately; the mines get faster, and therefore harder to avoid; the cannon’s shot moves faster as well, so you really have to be careful about going in too close for the kill. Basically, it all gets a bit Benny Hill.

Released in 1980, Star Castle is obviously a product of late 1970s Star Wars fever, and capitalises on a number of plot points from that film: a tiny ship is sent to destroy a large, powerful, well protected space weapon against appalling odds. You get the idea.

It's difficult to overstate the impact of the original Star Wars - when released in 1977 it was groundbreaking in a way that few films are. In recent years I think of perhaps The Matrix as being a similar cinematic watershed. Even Avatar, as much of a technical tour de force as that was, didn't have the impact of Star Wars. It's therefore no surprise that, when we look at videogames from that era, space shooters dominate in popularity.

But anyway, I digress...

Star Castle sounded awesome, and it looked awesome, but I’d never even heard of it until last year when I watched the Atari: Game Over documentary. That’s how I found out it was the seed that grew into Yars’ Revenge, which I had heard of.

Howard Scott Warshaw, the famed Atari 2600 game developer – who was rather unfairly blamed for bringing down Atari after the E.T. debacle - is interviewed in the film. He relates how he’d intended to create a version of Star Castle for the 2600 but didn’t feel it wouldn’t work well on the system. He felt it wouldn’t be possible to create a good version on the 2600, as a result of which Star Castle transmogrified into Yars’ Revenge.

And when you look at the two games: their mechanics, and their objectives, the similarities are definitely there. In both games you have a protected enemy that you can only destroy once you’ve reduced its level of protection. In both games that enemy is armed with a powerful, and very dangerous, energy cannon. And both games are brutally hard.

Yar's Revenge - a mad festival of psychedelic visuals and disturbing sound effects... not to mention a ton of fun.

The upshot was I decided that Star Castle looked incredibly cool. Have another look at a screenshot from the arcade game.

Another screenshot of the arcade version of Star Castle in which the coloured screen overlays are clearly visible.
This screenshot is, I think, from the cocktail version of the game. I believe the standard upright cabinet was the more common variant though.

Aren’t those vector graphics awesome? Crisp, bright, and extremely stylish.

The colours actually come from transparent coloured overlays on the screen, which you can clearly see in the above screenshot. The vector display itself is monochromatic, just like Asteroids and other games of that era.

Despite it's current niche-iness, Star Castle is clearly loved by those in the know. And one of them, D. Scott Williamson, set out to prove Howard Scott Warshaw wrong about Star Castle being impossible to build on the 2600, with the result that in 2012 he finally released an awesome version for the console following a successful Kickstarter campaign.

Here's a video of the 2600 version. Look how cool it is, especially when you consider the extremely limited capabilities of the console.

A great review, and footage, of D. Scott Williamson's Atari 2600 version of Star Castle.

Again, in fairness to Howard, he himself says in the Atari: Game Over documentary, that the development time for most 2600 games was something like five to six months. On that kind of timescale I can believe it would have been difficult, if not impossible, to create a really good version. I believe D. Scott Williamson spent years building his version for the 2600, and there was plenty of trial, error, frustration, and disappointment along the way. So, on a normal commercial timescale, never mind the weed and alcohol fueled corporate culture of Atari in the early 80s, I can't really blame Howard for saying it couldn't be done.

Anyway, I digress. Again...

I wanted to play something with that sort of cool late 70s/early 80s vector vibe, but was frustrated when I couldn’t really find it.

There’s a Flash version of Star Castle on the web, and an old desktop version for PC and Mac that looks really cool, but it crashed at the end of every game for me. And then there’s the odd mobile version that’s hard to control.

Net result: I decided to try my hand at making my own web-based version, which became Star Citadel.

Screenshot of Star Citadel - it looks similar to Star Castle, but definitely has its own identity
Screenshot of Star Citadel. As you can see, it looks a lot like Star Castle, but definitely has its own identity. Here the player is mashing the defensive shields, but the cannon has already deployed a mine, which is homing in on the player's ship. The other two are still bound to the shields, but that won't last long.

Star Citadel isn't exactly like the original. What I was really looking for was something that had the feel, the aesthetic, of the original, but which was also more accessible to modern gamers, who aren’t necessarily so keen on being punished viciously for every tiny error. I don’t need to do that because I’m not trying to get people to put quarters (or 10ps, here in the UK) into the machine all the time.

I wanted a more gradual learning curve, coupled with a really fluid and smooth playing experience, but something that captured the vector-coolness of the old version. I love the Tron-ish feel of the whole thing.

I’m also a big fan of Cowboy Bebop, so I wanted something of that sort of vibe about it – hence the funky soundtrack, which I licensed from PremiumBeat.

For purists I've also added a classic mode, which offers play mechanics that are much more similar to the original arcade game. It does still have the updated graphics of my modern interpretation though. Game mechanics can't be copyrighted but graphics certainly can so I wasn't about to just rip them off.

And that’s the story of how Star Citadel came to be. I hope you like it, and please let me know if you have any comments suggestions. You can contact me using any of the methods here.

In the meantime, you should definitely play Star Citadel right now.