I haven't played the original SRB2 level pack in a long time, but nice work on this. The texturing is really great.
There are a few issues ... some of the lighthouse doors in the Emerald Coast aren't really aligned with the springs. The checkpoints can be too far apart at times in most levels, but maybe you don't want to change that from the original.
A few of the levels live up to the original Dreamcast/Gamecube version. Sky Deck is better than the original IMO.