WebLiero strives to be as accurate to the original as possible, and from what I can tell recreates the physics, objects, and particles systems using the same general structures as the original. It derives its physics constants and other gameplay data, including weapons definitions, from the original game and optionally can swap definitions from a selection of the original Liero's mods. Similarly new custom mods can be created, see my other comment in this thread.

It is worth mentioning that officially Liero has been recreated and is an open source project. So the details of the physics engine are now public. The code for v1.36 is a modern rewrite of v1.33, of which the source code has been lost. See https://liero.be/ for more history.

Yes, I did try WebLiero out once I had the opportunity, and it indeed feels just like the original. Incredible job by the authors.

The number of remakes really was a homage to how incredible the game is. I remember myself and my friend on the floor crying in laughter over some modded Liero shenanigans. As far as I remember, the original Liero webpage described Liero as a game built around an idea for physics - so replicating said physics isn't entirely trivial.

I also recall that OpenLiero was doing a "whitebox" implementation of the physics (much like OpenRCT). That project should be pretty close if you're looking for something run on your desktop.

This page is 1000% spot-on. My muscle memory even kicked back in, after more than a decade.

Same here, I still remember young me and my friend crying of laughter on the floor playing this game :')

It seems digging is much slower than in the original. Otherwise it's very similar.

I haven't noticed it being slower, but you can also bind a single key to the dig action (original Liero didn't have that option), which in my experience results in much faster digging than with the old hold forward + tap back combo.

This is a port of the original Liero, so 100% accurate physics.