Insector is an old school bug chasing/shooting game by Gottlieb programmed by Tim Skelly. The developer who did both Screw Loose and Reactor - both games having already been featured as GOTDs.
Unfortunately, both Screw Loose and Insector never saw the light of day - dying in prototype stage. Thankfully, they have been resurrected by the magic of MAME.
Like many old school games I like, Insector benefits from a creative concept an interesting, open design, and unusual controls. You are an aerosol can of bug spray (not many games use that as your avatar), constantly shooting out a stream of death no matter where you go. In fact, you don't even need to push a button to shoot out your cloud of goo, it just is happening all the time. There is one other weapon that fires when you push a button, a bomb (sort of). It shoots out left and right from you simultaneously when you push the button. That means left and right as far as the screen is concerned - regardless of what way you currently face. It is a powerful weapon, but it is inhibiting that it only shoots out along the horizontal parallel. Your main weapon, the cloud coming out of your can, is always firing in the direction you are facing, thus leading you all the way. This can help protect you as you run around, but it can be difficult as you are being chased (and running away like a wuss) because you can't fire behind you, only the direction you face.
The levels progress nicely. You have to collect jewels for points and kill all the bugs. Later come Queens and snakes. The snakes are everywhere and difficult to battle. Also, soon the game becomes two levels. Grey bricks make up an upper level and crawly things harbor below. You have to use your bombs to blast the bricks, exposing the lower levels. It's cool to see the color outline of the bugs and snakes through the edges of the bricks.
There is also a bounty zone - kind of a bonus zone but you can still die if a bug munches you.
The music is a strong indicator as it ramps up in pace and pitch as the round goes on and the bugs get faster. I can't be sure of this, but it SEEMS like the more you use the bombs (they are unlimited) the faster the bugs chase you. Either way, they certainly do get faster as the round progresses and you kill some of their friends.
Insector is another example of an interesting game that quickly becomes compelling. It doesn't have great graphics or sound, but the inventive gameplay - especially the constant running away and between the crazy bugs - makes for a fun time.