I did? Actually, that's a top-down shooter. Sierra actually did have a first-person mode in Manhunter: New York, and if you notice Robin's little tag line on his posts, he claims to be able to make a Doom-like with AGI or SCI. And he's right, you can. I didscovered that you can make a platforming game or RPG or even a Rogue-like with AGI. It's a language, so you could even make a crappy database with it if you wanted (Lotus for AGI?). However, every language is developed for a specific purpose. LISP is great for AI, and crackdotcom actually made the arcade game Abuse in it, just to prove they could. BASIC was largely created for non-programmers and beginning programmers. The name says it all. Hell, my old lady is Visual Basic certified and she has no clue what I do at my computer all day. This isn't to say you can't make attractive games in any flavor of BASIC. There are quite a few amateur games made in VB that look all right. It's just that VB wasn't made to make games. AGI is optimized for a particular brand of adventure games. It's cool to throw in little arcade sequences and other enhancements, but at its core, it is designed to display certain kinds of graphics and sounds and parse input in a specific manner. Hell, I'll use Klik'n'Play if it gets the job done the way I want. (Actually thinking about this if I can score a free copy; I think it is free...). Anyway, I'm promoting Python as a next generation adventure programming environment because I'm impressed by its portability and its nice graphics and sound handling routines (especially those of Pygame, a set of libraries for Python), the fact you can easily embed C code into Python, and its key-handling routines are easier than C.
However, I will say that if you decide to use BASIC and can make a good game, more power to you. This isn't me taking an anti-Micro$oft political stance... just trying to steer you towards some more effective development options.
By the way, if you're looking for 3-D Engines, check out the
http://www.the-underdogs.org --Home of the Underdogs and its affiliates. Game Hippo is also good (It's through Game Hippo that I first encountered AGI development). They got the goods you want.