Loom seems to be a perfect example of a game that is completely focused in what it wants to accomplish. Instead of trying to include all of the game mechanics he possibly could, it appears that Moriarty thought long and hard about what were the minimum game mechanics necessary for the telling of his story. He then eliminated everything that did not truly add something to that story. This had the result of greatly simplifying the game, while at the same time making it considerably more elegant and easy to navigate.
The game was developed using the SCUMM Story System, which most of LucasArts adventure games have used in one form or another. Credited to Ron Gilbert and AricWilmunder, SCUMM stands for Script Creation Utility for Maniac Mansion, so named after the first game to use the system. Indeed, if one looks at the other LucasArts adventures , one will notice that nearly every one has much more in the way of gameplay mechanics and user interface than Loom . Both Maniac Mansion (1987) and The Secret of Monkey Island (1990, the same year as Loom ) include inventories for players to manipulate, in addition to allowing players to click on a variety of verbs that can be used on various objects in the game world. Both games were created using the SCUMM system, indicating that inventory and verb systems were readily available to Moriarty via SCUMM if he wanted to use them. Indeed, inventories and verbs were a very common element of nearly all of the adventure games released prior to Loom . (Many adventures released since Loom have done away with both verbs and inventories, most notably Myst and its many imitators.) So Moriarty was making a tremendous break from both the SCUMM system and tradition when he left these mechanics out. Including an inventory and verbs could have added a lot of depth to the game if the story was reconceived to take advantage of them. But as it stands, the game functions perfectly without them.
Many other adventure games also feature branching dialog trees. In this sort of system, when the player character is talking to another character, players are presented with a list of different sentences their character can say. Players can then pick from those choices and some level of interactivity is achieved during the conversations. Again, The Secret of Monkey Island featured exactly such a system, used by the game s creator, Ron Gilbert, to enormous gameplay payoff, particularly in the classic sword-fighting sequences. But, as with the verbs and inventory, there are no branching dialog trees to be found in Loom . Instead, when the player character talks to someone, players just watch the conversation unfold as a non-interactive cut-scene, unable to control it. On one level, this would appear to remove a degree of player interaction with the game. But, in the final analysis, the branching conversation tree systems always contain a finite number of branches, and hence most such systems devolve into players simply clicking on each of the options, one by one. ( The Secret of Monkey Island is one of the few examples of a game that actually adds depth to the gameplay with branching conversations.) For Loom , Moriarty went with the cut-scene conversations since they were the most effective system for conveying his story. Again, Moriarty was focused on his storytelling goal, and he let no adventure game conventions stand in his way.