8 days before the release, you post the Brown Para-goombas (World 1 is their debiut.
7 days before, you post the Cannons (By world 2 all variants have been seen)
6 days before, you post the new water enemies (Boss bass, lava lotuses, blooper nannies, etc)
5 days before, you post the bulls-eye bills
4 days before, you post the fire nippers and flame chomps
3 days before, you post the puddle cheep cheeps (the cheep cheeps that hop between set pockets of water) (All other world 6 enemies either are in the base game or have been made before)
2 days before, you post the Spiny cheep cheeps and a random enemy spawner (a more accurate way to remake smb1 levels)
and the day before release, you post cannon bob-ombs (SMB3 Bobombs that ignite after a while, but act differently to smw bob-ombs), Respawning Rocky Wrenches (red on the original NES' World 8), Laser Statues, diagonal thwomps, and standalone Bowser fire that can be placed anywhere (and work).