Does Enlighten Brick mainly produce copies of old LEGO sets?
Enlighten Brick is a Chinese LEGO knock-off brand.

A lot of, if-not most of, the sets the produce are basically copies of existing LEGO sets, either current ones or popular retired ones.

From their website though, they do appear to have some of their own designs.

Edit by Phil B: Word of Warning: By buying counterfeited sets (such as these Enlighten Bricks copies of LEGO sets) you are sponsoring illegal activities, which if not stopped might ultimately cause irreversible damage to the LEGO brand and the high quality, original sets it provides. Enlighten can offer sets for less than what the equivalent LEGO set would cost purely because instead of investing in R&amp;D they have stolen LEGO's Intellectual Property.