Playing just the normal levels, not even bothering with the secret exits. The levels are actually pretty hard, though I feel like the challenge isn't really structured in the levels themselves. One issue I keep running into is that HDMA gradient. I know it looks cool but it obscures the foreground and the sprites, and when it does that it affects the gameplay because it can make it harder to see certain parts due to the vertical scrolling rampant in the levels, which can lead to certain situations where you fall into a pit by accident because you couldn't tell that there was no bottom due to the ambiguity given by the gradient. I'm glad it was only a few levels.
Overall, pretty average.
PS: Also, there were a few random graphical glitches where the level doesn't load properly, resulting in messed up areas that can potentially mess up how the level design is conveyed to the player, though I was playing on a real SD2SNES cartridge on a real SNES instead of an emulator.
Great hack! Nothing to complaint about, just an orange pipe in the water level which takes Mario to the test level. Other than that, I enjoyed level design and getting the coins in the levels. Keep up the good work and I'm looing forward to playing the next demo or the complete game!