> the original DOS games

"Total Wormage" was on the Amiga, which became the original Worms. It was ported to other machines after:

https://en.wikipedia.org/wiki/Worms_(series)#Development

https://worms2d.info/Total_Wormage

> an expansion to the original

Not sure about DOS versions, but Worms: The Director's Cut is a heavily-expanded version of the original: more weapons, custom levels (allowing 16 colours instead of 8, IIRC), etc. Highly recommended!

You might enjoy Liero (or its modern descendent OpenLieroX) which is similar to Worms but with real-time play (and kept the pixel vibes).

Same - I always preferred the pixel art look to the smooth cartoony look!