Playing an Alex Kidd game, any Alex Kidd game, for the first time is like playing Super Mario Bros. 2 for the first time. It's not quite what you expected. Lost Stars is closer to the original formula than successors Alex Kidd BMX Trial and Alex Kidd in High-Tech World (the latter, like SMB2, a game from a different franchise rebranded for the American market due to Sega's mistaken belief that Alex was a commodity), but much simpler.
Alex Kidd - The Lost Stars is, in a word, easy. Alex zips through a series of worlds (including the obligatory underwater stage) looking for lost Zodiac signs. Each level is timed and getting to the end is mostly a matter of memorizing the locations of the platforms and enemies and running through without stopping.
I will give Lost Stars credit where it's due in one regard though. The game is gorgeous. Graphically, it blows away all of the 8-bit Mario games. Too bad that in no way makes up for the lack of challenging and diverse gameplay.