use of undefined type

[Andre W B Furtado]

I'm developing a tool that will help game programmers to develop games in
Haskell. To create a game object, the programmer must call the function
*object* as follows:

object name_of_object position_of_object speed_of_object

I would like also to add another param to this function, which type would be
anyone defined by the programmer. Unfortunately, as Haskell does not allow
things like:

type Game = (Name,Position,Speed,t)

where t is an undefined type, I'm forced to add "t" to the left side of the
type synonym (type Game t = ...). But this is realling doing a mess in my
code, since I have to pass this "t" all around. That's why I ask if anyone
knows another idea to solve this problem...

Thanks a lot,
-- Andre W