There are several different creature types. Try to hit the fast moving flying white "tissue" creatures early on at a distance so that they will destroy themselves before pushing you too far back.
The genesis for this game came from many years ago playing around with the "car shooter" while developing a post-apocalyptic racer called Powerslide with Ratbag. I'd sometimes get bored while evolving AIs and set up at a spot on the track facing the oncoming racers and try to hold them back by shooting cars at them. Matching their mindless determination to proceed with my mindless determination to retard. I kept thinking there had to be a little game in there somewhere.
In the unlikely event that you have a working copy of Powerslide (though statistically much more likely than anyone having played this game) you can access the "car shooter" by typing in the cheat code LAUNCH. You then hit "a" to launch a car and "z" to move in the direction you are facing.