Firstly, this reviewer will probably need to start off this article with an elaboration for the framework behind this game.
This game, Shanghai, is based on a single-player game known as mahjong solitaire, which is allegedly an ancient children's game (that involves using Mahjong tiles when the adults aren't using them themselves) and had been named as thus for lack of comparisons that are better than that with the card-based solitaire. The name for the digitized version, "Shanghai", was actually trademarked by Activision in 1986; the reason for this choice of name is not clear.
Mahjong solitaire requires the construction of a ziggurat-like edifice of sorts using Mahjong tiles. Then, the player has to deconstruct the edifice by removing matching pairs of tiles as they gradually become exposed (i.e. their faces are completely unobstructed). In the case of the digital versions, the construction of the edifice is randomized.
While it does not contribute anything new to the concept of Mahjong solitaire, the GameBoy version of this game appears to be satisfactorily competent at recreating the tile-made ziggurat, which can be constructed in several different patterns. The calligraphy on the tiles are properly rendered too; there was no trouble (for this reviewer) at finding which tiles match which. However, the controls and the camera are a different matter.
The camera is zoomed too close to the tiles - likely in an attempt to make sure the calligraphy on the tiles have adequate clarity, which is perhaps more important than having a better view of the ziggurat. However, scrolling - which can be done by moving the selection cursor to one of the four edges of the screen - is a bit too slow (for this reviewer). As a result, a lot of time can be spent scrolling instead of matching tiles, if only to see which part of the edifice has a tile that the player would like to find.
Fortunately, there is a mini-map of sorts that shows the current location of the camera viewport on the entire plane of the ziggurat, so the player is not in danger of getting lost (especially in the latter stages of the sessions, when more tiles had been removed, leaving behind empty space).
It also has to be pointed out that while all randomly generated patterns of the edifice can be solved, some are generated such that dead-ends (where no more pairs of tiles can be legally matched) are more likely to occur than in other patterns. This could have been caused by limitations in the scripts used for generation, and the processing power of the GameBoy itself. Still, it is a minor issue and it serves to encourage the player to think several steps ahead. However, the aforementioned restrictive camera makes planning moves difficult.
There appears to be no appreciable music whatsoever in this game. Sound effects are also next to negligible. Fortunately, both are not required for playing the game.
In conclusion, while it is a somewhat faithful digital adaptation of the table-top version, certain design limitations to suit the GameBoy's capabilities makes it a barely decent video game.