After only recently working out what these actually were, and how they differ from the JP BotCon trio, I got my first JP Choro Q toys today, and had such a laugh with the Megatron one.
There are three moulds (Optimus, Rodimus and gun Megatron) and two decos for each mould (cartoon, and metallic/sparkly)... but the gimmick is the pull back motor on each.

Yes.... even Megatron.
And yes.... he's a gun.

So, transforming Megatron into a gun and laying him on his side, I pull him back and let it go.... and the gun just "drives off" on its own.
It is so funny.
It's like watching one of those couch cars driving around.

After doing that a few times, laughing with each one, I then pull back Megatron and say, "Decepticons, transform and roll out" and let go.
So funny.
To me at least...

(word of warning for anyone thinking of buying these - the "metallic" ones suffer from Brittle Plastic Syndrom)