Many miscellaneous changes occurred in order to remain faithful to the original Flash 2 game, including the unique font seen in the message boxes, the faster movement speed on the overworld, the lack of a timer, and the lack of lag upon Mario transforming between states, to name a few. Users would then copy that code that they receive in the submission post of their level, and then other users copy-paste that code from the site to their SMF2 game in order to load that other user's level. Then they had to get a code for the level which was done directly from within the game.
The game originally had a level editor similar to Lunar Magic where users can create levels. Now here's a fun fact: I've never actually beaten the main game of Flash 2 back then I just mainly focused on the Level Portal option the game had where you can play custom-made levels from users on Pouetpu. I remember playing this game on Pouetpu-Games when I was much, much younger along with Flash 1.