I like the vocals and the electric guitar. At least they sound reasonably professional (except for the few times the singer is out of tune).

The drums and brass sound "keyboardy". The drums sound like they are mostly a 1-bar pattern on repeat. The brass sounds "flat": no glissandos or (de)crescendo's. Can't tell whether they're Roland or Yamaha though.

There is little dynamics in the drums as well. It could use some cymbals to spice it up a little.

The elements you have added outside of OMB make it sound reasonably well, but the OMB-part sounds very '90-keyboardish.

This demonstration does not improve my appreciation of OMB