Silkworm began its overlooked life as a 1988 arcade shmup by Tecmo but I’ve always known it better as an Amiga game, one of those mostly forgotten home ports that, like Rodland, seemed to be more popular on grey-shelled computers in Europe than it ever was in its native environment.
If this was released today you’d be told it had asymmetric co-op, which is a fancier way of saying “Two playable characters who play differently from each other but do best when working together”. In this case that mismatched pair is a helicopter and a jeep, the two (or just one of your choice in solo play) both shooting mostly towards the right as enemies aggressively make their way towards the left. Playing as the helicopter feels like pretty vanilla shmup fare: You fly around, shoot ahead, collect power ups so you can shoot ahead more vigorously than you did before – you know how to use this one before you’ve even put the disc in. The jeep however is a very different beast, featuring a cannon on its back capable of firing at any angle between dead ahead and straight behind and the strangely cute ability to perform a little jump at the press of a button to help them avoid running into mines, terrestrial enemies, and anything else the helicopter could easily fly out of the way of.
And so the first thought that springs to mind is this is all just the usual difficulty select played out in a more interesting way: The helicopter is easy mode and the jeep is the equivalent of hard. Boom. Done.
What makes Silkworm so interesting is how acutely aware of the differences between its two “characters” the game is, deliberately manufacturing situations where they can hinder each other just as easily as they could help.
Enemies are designed in such a way that in most situations the helicopter’s non-issue is potentially a game-ending problem for the jeep, and vice versa: Tank-like machines can float in from above; if you shoot their parachutes they’ll drop to the ground below – quickly and easily getting them out of the helicopter’s way – their boxy metallic frames causing a sudden and potentially fatal problem for the jeep if they’re dumped in an unfortunate pattern or their numbers overwhelm them. If they’re not destroyed as they appear missiles emerging from silos buried in the ground are easily dash-hopped over by the jeep, leaving the helicopter trying to manoeuvre around a wall of tall instant-kill objects. Enemy planes rushing in from the sides don’t fly low enough to harm the jeep but could devastate the helicopter if not shot down, while tough walking robots can be ignored if you’re in the air but become a deadly wall on the ground. The examples are virtually endless, Silkworm possessing just a few “neutral” enemies that pose an equal threat to both playable craft.
The locations this unusual action takes place in are most honestly described as… an afterthought. You scroll past the same old perfectly flat ground and featureless mountains, or another sort of perfectly flat ground and featureless mountains, or maybe if you’re really lucky some perfectly flat ground and featureless water, and then the game will cycle back around to perfectly flat ground and featureless mountains but in a different colour. One of these alternatives palettes is monochrome. No “snow covered”, not “foggy”, but monochrome (these issues are also present the arcade version and not a weird Amiga-based limitation – I made a point of checking). These backgrounds are visually adequate and nothing more, showing you scrolling past a place of some vague sort before moving on to another similarly blah area with little reason to feel excited or any sense of continuity. The one bit of good news is Silkworm does at least make the effort to include wholly unique location art for its final stage and it’s got a pretty wild techy theme going on so there is a proper visual climax in there, it just takes an awful lot of single-plane mountain scrolling to get to.
Although it stands to reason that if one aspect feels like an afterthought, then it may be because its creator’s attention was focussed elsewhere…
The flat empty skies in those painfully average backgrounds make it easy to spot the swarms of tiny enemy fighters appearing in the distance, this visual embellishment your silent warning a big horde’s on the way and you should make some effort to prepare yourself for their arrival. The enemy sprites – available in any colour so long as it’s green or grey – aren’t exactly expressive but the way the windows are drawn just so gives the aircraft little angular angry faces, and they all have very strong silhouettes, making prioritising threats and keeping out of trouble come far more naturally than it could have in a game filled with wave after wave of green things. The regularly reappearing multi-part midboss-ish aircraft has a dragon-like quality to it, long moving neck and all, and assembles its various parts around a glowing core in an appropriately “magical” way. Bouncing green enemies have distinctive “frog legs”, even though they’re really just stocky helicopters flying in a low boing-y arc. Long sleek jets zoom across the screen at high speed in a flat horizontal line, been and gone before you even realised they were coming. Enemy helicopters have an almost wasp-like look to them that suits their hovering around and irritating “stings” well. Everything was created with a specific purpose in mind, and Silkworm sticks so closely to its own rules you not only become aware of this but also learn how to use it to your advantage during your very first go.
A linear and very ordinary set of shot power ups are gathered naturally during play, complimented by a far more interesting shield system. These temporary items grant complete immunity to everything for a short while, and pop up so frequently you’ll more often see several of them on-screen at the same time than you will one all by itself. Now, let’s keep Silkworm’s co-op play in mind…
You need them, and your co-op partner will need them just as much as you do too – this instantly creates potential conflict over a precious resource. But if you make a point of carefully sharing them out then there’s the problem, right? Well. They don’t always appear in places the jeep can jump high enough to collect, and sometimes are so low the helicopter can’t grab them either, so it’s not always possible to distribute these life-saving shields fairly even if you want to. But what both players can do is shoot any uncollected shield on the screen until it explodes, which will helpfully destroy every non-boss enemy on screen – and may also deeply annoy the person who was just about to pick it up, their few precious seconds of absolute safety gone in a flash in favour of a short breather and screen-wide destruction. It’s a fascinating idea that not only offers two functions in one item but also asks if you’re prepared to sacrifice your own – or your teammate’s – more generic safety in favour of what might be “the greater good”.
Silkworm’s not the greatest shmup there ever was, but it’s definitely a better game than its tanks and helicopters setting would have you believe and if nothing else deserves to be recognised for its unique and inventive approach to cooperative multiplayer.