Yoshi decides to move away from Dinosaur Land to a nice peaceful land named Acacia Valley, the valley of love. Iggy Koopa has been spying on Yoshi recently and realized this, alerting King Bowser, they organized a plan to ambush Yoshi and Mario! It's up to Luigi to save the day, and nobody is going to stop him!
The design is well made. It's pretty basic, since we're on a first world, but it still manages to be fun to go through. There are some mino flaws here and there (like the fact that some of the sections can't be passed if you have a Yoshi), but nothing too bad. For a world 1, it's a good hack.
Aesthetics are nice as well. The levels keep a vanilla-ish feel, with very small edits to the original GFX. The overworld graphics are almost totally changed, and they are very good looking.
Overall, a good demo. I'd recommend it, that's how a first world should be like.