No prizes for guessing the classic arcade game that’s the inspiration for this latest enemy – yup, it’s another of Atari’s masterpieces – Centipede! Working title for this enemy is the ‘Scuttler’ (I already have a ‘Crawler‘ and a ‘Squirmer‘)!

The mechanics of this enemy are pretty simple, I thought the hardest thing to get right would be the algorithm that makes the segments ‘follow’ the head (I’ve had to right similar code in the past and got myself into a right mess) but the code I came up with, unbelievably, worked pretty much right of the bat!

There’s probably a better way of doing it but my basic approach here is to ‘remember’ the direction each segment is travelling and to continue moving in that direction by default each frame. If the total horizontal and vertical distance between one segment and the next is less than the desired segment spacing no movement occurs. If the segment aligns horizontally or vertically with the segment in front we switch orientation (i.e. from horizontal to vertical or vice versa). This seems to work well enough for my purposes but if anyone has any better ways of doing this I’d be interested to hear them as it’s a gamedev problem I seem to run into quite a bit.

Unlike the Atari Centipede I don’t have any mushrooms to run into to initiate a change of direction so I had to improvise a bit here. Changing direction when it hits buildings was an obvious one, but I also have it switch direction when it hits the edge of the screen (i.e. camera area) and, with a certain amount of leeway, when it aligns with the player on the opposing axis. This approach seems to maintain an authentic ‘Centipede’ feel whilst working within the confines of the Jetboard Joust gameplay.

I also added a slight ‘sway’ to the segments as they move as a fixed horizontal or vertical movement just seemed too ‘static’ in context even though it would have been truer to the original game. I want to tip my hat to these classics rather than slavishly replicate them.

Of course I also had to have the centipede splitting into two when it’s health is reduced which means things can get pretty manic (in a good way, though I’ve toned it down a bit since this video as things were getting too out of hand too quickly).



I’ve also been working on a Centipede style retro arcade palette (see the GIF below) but have been running into a few issues trying to get this to look good across all sprites. The red outline you can see is used on some of the sprites in the original arcade game. I like the way it looks here as I designed the sprite around it but it looks terrible on many of the sprites I’ve already designed so I think I’m going to have to use a more generic approach. If I ever make another game I’m going to make sure I treat my outline colour as a completely separate part of the palette – lesson learned!



Oh yeah, an accidental result of this that I really like is the fact that, on the scanner, these enemies look just like a version of the original mobile game - Snake! As I spent 15 years or so writing mobile games this seems somehow appropriate!

Dev Time: 2 days
Total Dev Time: approx 253.5 days