That would certainly be interesting. Crafting + randomized (to an extent) but internally-consistent physics would be very interesting to play...
"So I put the crushed yellow rock into the spotted deathbug blood... AYEEE! GAS GAS GAS! RUN AWAY!!!"
"OK, not doing that again. It corroded all the metal in my lab... Might make a decent weapon against the bronze gatorbots though..."
OH LORD YES! YES PLEASE! In situations like this, I wish I took up coding instead of what I'm doing now. However, I don't think you could randomize physics per se, since that would result in very alien worlds, the world must be a bit anthropic-principley so that it won't look like designed by H.R.Giger and H.P.Lovecraft's child tripping balls.
Hmm, actually, I think it could be done in a Roguelike style or text-based kind of thing (Hell, think HFS in DF!)... those appear to be the most non-constrained in terms of what you could do with the world, so if you type 'Eat my boots' you don't have to make an animation of the character taking the boots off and chewing them, but can instead concentrate on the result. The randomization would be a problem with graphics, and text form fixes it, so the deathbug may have bluish chitin and 7 legs in one world and light-yellow starch body covering with 3 legs in another, and in yet another it may be actually a 90 feet tall Tokyo-smashing monster.
To add even more fun, they wouldn't have pre-set names, but descriptors, yet with the ability to set nicknames for them, so, say, each bluish toxic bug with 7 legs would be labelled a 'deathbug', and let's say that even if it was only a similar creature, but non-toxic would be called 'unusual (X)', X being the nickname.
Now, to the Code-mobile! Err, please? Someone?