1) It will be slower than other compilers. VB4 is not a compiled language, it is interpreted. This means that every time your program is run, it is converted from a version of code that is closer to machine code than straight VB, but not quite machine code to machine code. This takes time, which games need more of
2) Not many people use it. VB is up to version 6 now, with the next version due out soon. There are a few people still using VB5, but most people writing games use 6. This means that it will be harder to find help.
3) Finding something that looks like it has lots of restrictions and breaking those barriers and then showing people and saying "Hey, look what I did... in VB4" will be really satisfying. There are enough people around who think that VB6 itself is too slow for games, and whenever I finish a game, it makes me very happy ... but I think finishing a game in any language is very satisfying, and since I''ve never finished (or started) a game using C++ (the language most people here use), I don''t know what that is like .
4) It will be a learning experience. Learning a programming language, be it COBOL, Perl, C++, VB, Pascal, C, ASM or whatever will teach you a lot, and what you learn in each thing will apply to other languages.
So, if I was in your position, I would probably play around with VB4, and see what happens. You might love programming and want more, in that case, think about an upgrade to a more recent compiler.
I used to program in QBasic (slower and more limited than VB4 =), and I loved it, so as soon as I got a computer that could run VB, I went out and bought it. Maybe you''ll be the same, who knows.
I''d just say, try it, and if it doesn''t work out, you may try another language/compiler. VB4 however is known as the slowest VB version ever, so even if you make games with it, you''d better recompile them with VB 5 or 6 when you are doing a release (there are enough people who have a copy of vb lying around somewhere on their hard disk, ask one of your friends to compile it for you - there''s nothing illegal about that I guess)