Silk Worm is a horizontally-scrolling shooter for the NES ported from a Tecmo arcade game. It is the predecessor to SWIV and Firepower 2000, and was also ported to several home computers. Like those other games, it allows the control of two different types of vehicle, a helicopter or a jeep, each of which plays very differently, or can be played cooperatively with one player controlling each. However, unlike the other two games mentioned, Silk Worm's horizontal play makes playing as the different vehicles even more disparate, as they feel completely different from one another.
The helicopter feels almost like playing Choplifter, only a bit simpler in how you aim and fire, with faster response made for the arcade feel. You tip up or down as you move backward or forward, though you can hold the A button to stay tipped downward regardless. In many ways it is the easier vehicle to play as, as you have the entire screen to use for evasion, and you have a dual shot at the get go. It can be powered up with an improved shot and rapid fire as well... but the jeep is cooler.
The jeep is of course earthbound, but it does have a surprisingly useful jumping ability to help dodge. Its weapon is a top-mounted turret that can be angled with the up or down arrows, and it can also power up with a twin shot and rapid fire. The jeep's shot is more powerful as well, and it can tear through the bosses in a hurry. Honestly, playing as the jeep feels more like a run 'n gun, and I mean that in a good way.
Aside from the powerups mentioned, there are also point bonuses and shields, which appear from destroying ground platforms. Grab one for a few seconds of protection, or you can blow them up and they'll act like a smart bomb, destroying all but the more powerful minibosses. Collecting powerups causes you to rank up as well, and at the top rank, point bonuses increase in value and you no longer lose your powerups after dying. Sweet!
Silk Worm is great 2 player, but single player can vary. Personally, I think playing as the jeep is immensely more satisfying, as it has a much more unique feel like an auto-scrolling run 'n gun instead of a pretty average shooter. It really elevates the experience for me. Playing alone as the helicopter just feels like another shooter, and is way outclassed by the likes of Gradius or Life Force. The graphics are tiny and unimpressive, but they do a passable job, and the music, while there's not alot of it, is good for what exists.
Played this one? Any good co-op memories?