yes, why woudn't it?

creatures are not "pushed" anywhere, thats not what the text says, it says that the creature moves into a space 5 feet away from the cube of its choice, so the, in your example, the minotaur should have been able to choose where it ended up instead of being forced into the nearest empty space, but otherwise you did it right  

eheheh magic hoover

Quote from Gamie_Parrot >>

When in said Gelatinous Cube you cannot breathe, BUT you only take acid damage, instead of shortness of breath damage.

 You might very well die from acid damage (basically, being digested inside the cube) before you die from drowning or asphyxiation. Drowning rules let you remain conscious (if you are surprised) for a minimum of 1 melee round + one round for each point of constitution bonus. If you "held your breath" before being engulfed by the cube, you can hold your breath for a minimum of 30 seconds (5 melee rounds) + your con bonus.

If your constitution is 11 or less, you'll be at zero HP by the end of your turn and then you die if you were unable to hold your breath before hand. A level 4 or lower character with a 16 con would likely die from the 21 points of acid damage each round unless it was able to make a successful strength check to escape the grasp of the cube in two rounds. 

If the rest of your party manage to kill this monster, at least they can still recover your...bones! Revivify won't be able to bring you back though. Talk about an inglorious death! "Hey Bob, how did your character die?" "Uh, I got engulfed and digested by the jello monster. didn't even see it coming!"

So if you are a warforged made out of metal only you can live in a gelatinous cube?

Quote from bampy >>

I will try to eat cube

 Funny story my friends Dhampir player bit it the DM said it was sour *shiver glad I didn't*

Why does it look edible? Why do I want to eat the jelly looking cube? I don’t even like jello. 

lost my very first character to a cube waaaay back in the 80s

I made a castle where these were modified to be sewer cleaners.  One of my players earlier encounters was fighting off guards with the cleaners pressuring them to hurry out of the sewer.  Good fun.

what is the appropriate level to fight one of these with a party of 3 or 4 because this looks like it could easily TPK a low level party

I am confused how to kill it

Quote from Varis_the_hunter >>

I am confused how to kill it

 It doesn't have any damage resistances or immunities, so you just have to beat/magic it to death.

Can these things hear? Would Vicious Mockery affect it?

Im melting it with fire :)

wall of these  could stop an army

Dexterity is the main ability that initiative uses, so you should use that.

What are their weaknesses, I am tired of being killed by these guys.

Gelatinous cube + Clay golem = mid level threat. The cube gives the golem total cover while it is healed by the acid.

The cube would probably sink to the bottom if it contained heavy remains, otherwise it would float. There is also a concern that it would take acid damage as it desolves in the water (probably 2d4 acid)

A warforge would take damage but not have to breathe. A Clay golem would benefit from the acid. However if a warforge has an item that granted immunity to acid, then it would work