I can't see the point in not getting rid of the old tiles first, nor can I see the point in not cleaning up the crap off the floor before you even start. It looks better than what is was, but I just think it's a cheap and dodgy solution and a cheap patch up job. Sorry that's my opinion, no offense.
I’m glad it is plastic panel but it do look like it will be difficult to clean with those grooves on a non-flat surface. Korea gets really humid in the summer. However, for a commercial space, this is economical.