Even though I liked Super Mario Land quite a bit, it had many flaws. The graphics were awful, and the controls were not up to par for the Mario series.
The graphics in the second game were near-SNES level minus the color. The gameplay however was a bit different from the past Mario games. A bit more freedom like Super Mario World, but with a lot of exploration like Yoshi's Island or Warioland.
Speaking of Wario, this was his first game. He was also the game's final boss. He was a tough son of a bitch from what I remember.