I personally think this is 100% okay.
E1--------12----------|
B2--12----------------|
G3---12--9----9---12--|
D4--------------------|
A5--------------------|
E6--------------------|
Practically this riff the whole way. Classy song.
This here is my own version of the 'DECK THE HALLS'. it's COOL!
E1-----------------------------------------------------------------------|
B2--15-13-12---------12----12-13-15-13-12--12h13p12----------------------|
G3----------14-12-14---12---------------------------14-12----------------|
D4-----------------------------------------------------------------------|
A5-----------------------------------------------------------------------|
E6-----------------------------------------------------------------------|
Enjoy!