One of the most important advances in recent IF is what might be called player-friendliness, meaning the game's capacity to supply logical inferences. Michael Gentry's Anchorhead was a particularly good example of this: not only did the game have a large rucksack-type object (a trench coat, in that case) that could hold everything in the game, but it also handled the bulk of the item-juggling for you, so that you put items into and take them out of the trenchcoat automatically when you needed them. Likewise, you had a keyring, and when you came upon something you wanted to unlock, the game automatically sorted through the keys on the ring and checked whether any of them were the right one. Not many games do as much as Anchorhead to help out the player and keep annoyance at bay, unfortunately, and while Volker Lanz's Intruder is a good effort in many ways, the frustration factor is very much a problem.

It seems you're a private eye hired to break into a house by a woman who wants evidence against her husband for their divorce proceeding--though it's more like coercion than hiring, since the woman threatens to have your creditors start collecting on their loans if you don't help out. At any rate, you do indeed break into the house, and the initial goal drives what you do in most significant ways for about two thirds of the game. At that point, you start trying to find something else, and how you know what you're looking for or where it would be escaped me completely. It's true, of course, that no IF protagonist ever really feels content if he or she leaves doors unlocked, but there's a difference between pure exploration games--fantasy, in particular, where it makes some sense to look under every stone--and others where you have a defined goal that doesn't include playing magpie. It's one thing to have ill-defined motivations throughout the game, but it's another to have very clearly defined motivations that don't in fact shape everything you do. (Well, they explain the importance of what you eventually find, but you get no hint as to why you would start looking for it originally.) It might have been helpful to actually throw in some of your mental processes: "your thoughts now turn to matter X, and you wonder whether it's possible to find object Y." At least, that would keep the plot moving.

Complicating your task in addition is a _very_ small inventory limit, a finite light source (which is pretty easy to exhaust), a fairly restrictive time limit, and a puzzle that requires massive amounts of logistical planning and traipsing around. None of it is illogical per se, I should stress--I can't say that logic is advanced by infinitely large rucksacks, flashlights that last all night, and such--but sometimes cold logic and realism are not the friend of an IF designer. One particularly frustrating puzzle in Intruder necessitates either that you walk around turning on every light in the house or wander around in the dark, which is simply irritating, and while there are several clever puzzles (though some are old chestnuts), the annoyance aspect is considerable. Intruder seems to put a premium on having to do silly little things, like locking your car door before breaking into the house, and while it makes sense, these are the sort of gaps I'd rather just have the game fill for me. (Also, the hints only cover the first third of the game, which I found frustrating, since the puzzles for that section are pretty easy.) It's also annoyingly easy to lock yourself out of victory.

Technically, likewise, Intruder is a mixed bag. One container object does not suggest that it is openable, another suggests that it's unlockable when it's not, and the syntax for another puzzle was a total shock to me. There are various little things that bothered me--dropping objects down a hole elicits a "you hear a sound as if something's breaking," even if you dropped a key or a bolt cutter, which aren't in fact likely to break. There are some typos and writing errors as well, but the bulk of the problems are design-related, and they diminish any potential for immersion considerably.

The frustration factor is all the stronger because there's plenty to like about Intruder in other respects. The backstory is well done--it's rare that you have a PC with such a thoroughly defined set of motivations--and there's an actual reasonably believable plot. The characters--you and the woman who hires you, and to some extent her husband--come across very effectively; the author spends enough time developing each character to make them understandable and not caricatures. The setting itself is well described without excessive detail, and most of the objects and locations make sense. The tedium distracts from the story, unfortunately, and the logistical-planning aspect makes Intruder less a story than a set of tasks. In short, the story of Intruder has plenty of promise, but the implementation of the puzzles gets in the way.

Intruder isn't a bad effort, at bottom, and it has its moments. If you canoverlook the design flaws, it might be worth a try.