Fans of Mean Streets rejoice-- Martian Memorandum is an unadulterated, 100% pure point-and-click adventure game with no inscrutable flight sim or action portions in sight. Some puzzles do require you to solve them within a time limit, but usually it's quite lenient (once you find WHERE all the items are, of course). The characters you meet, as in Mean Streets are interesting, and advance the game as they would in a real murder mystery novel. You can select several approaches in your conversation, ranging from friendly to threatening, and different characters require different approaches (as well as cash) to cough up the information you need.
In contrast to most other adventure games, you can get irrevocably stuck if you pick the wrong approach for a character, who is so upset with you that he/she won't talk to you again. Typically, you will know when the conversation "fails" (mostly because everyone you can talk to in the game has at least one important clue), but sometimes the signs are more subtle, and you can proceed with other matters for a long time without realizing what you miss. It's a bit annoying, although not difficult to overcome if you use the tactic of "save before initiating a conversation, restore and play again to choose all possible choices." Other annoyances include extreme pixel-hunting, which requires you to slowly move the cursor all over the screen to find 1x1 objects. And-- die-hard fans take note-- there is a MAZE in this game. A big one. One that will require you to carefully map it, several times over. Fortunately, there is a way to bypass it, which makes it more bearable. There is also a very convenient built-in hint system, although the puzzles generally are quite easy.
Overall, a very well written storyline as well as good graphics and (some) speech make Martian Memorandum a solid adventure. The acting is as campy as ever, but if you like Mean Streets but abhor the flight simulator/action parts, then you'll definitely love Martian Memorandum despite all its pixel-hunting nuisance. Two thumbs up!