A weird, colourful, original worm-based race game on the ZX Spectrum, released by Romantic Robot in 1985.
Actually, Wriggler is less of a “race” game and more of a “crawl” game. The pace is not very fast at all.
You’re a worm, in a race with other worms, and have a number of route choices on the way to the finish line. How you make that choice is anyone’s guess, as the route of the course is not particularly well defined, and the going is continuously perlious.
On the way you to the finish line you have to avoid contact with creepy-looking spiders and other enemies, or otherwise see your Wriggler body stripped down to a skeleton and die.
Here’s a fairly in-depth look at ZX Spectrum Wriggler, from start to finish.
More: Wriggler on Wikipedia