Infidel is a rather humorless game that finds its protagonist exploring a previously undiscovered Egyptian pyramid in search of treasure and fame. It's a perfect setting for that oldest and most thoroughly explored adventure gaming oevure: the treasure hunt. Even by Infocom standards, the setting is quite deadly. This is a game that assumes frequent, unmotivated saving. That was a norm in 1983, and contemporary gamers/readers will be frequently frustrated if they are not willing to adopt the habit.
That is something students and enthusiasts of older texts (in a technical medium, 4 decades feels more like 4 centuries) must do, isn't it? Meet them where they are. Or were.
Mechanically, the "hook" that makes the deathtraps of Infidel unique is the system of hieroglyphs used to provide clues and identify the names--or even, sometimes, the significance--of objects and locations in the pyramid. Over the course of the game, the player's "codebook" will grow as they find and decipher new glyphs. These symbols are displayed as ASCII characters, so be sure your interpreter (if you are using one) has a properly selected fixed-width font (IMPORTANT: as in other games, use of these characters poses an accessibility problem for players who use screen reader applications). While I did like Infidel on a mechanical level, players who either don't or can't enjoy the codebreaking metapuzzle will likely have a less interesting experience.
If that were all, Infidel would be a nice, little game--short for an early Infocom puzzler but diverting enough. That isn't all, though. Persons interested in artistic or literary craft in interactive fiction--especially its history or evolution--will find its critique of the adventure game genre and its gamification of colonial plunder interesting. Reviewing the game's packaging and documentation is essential to understanding this facet of the game.
Infidel's initial critical reception is interesting to consider as well. Several persons have written about it in detail over the years.
My rating is highly qualified. If the codebreaking element sounds appealing, you will likely find this game satisfying mechanically. If the historical or craft elements interest you, Infidel offers a lot to think about. For those interested in neither, Infidel is a bit of a hard sell.