I wanna know few things:
1. Can I import custom-named list from OS?
2. I see there's grp Token. What is the use of it?
3. How does enemy's AI in platform games work?

I can help you on the 3rd one. Basically, you have a set of rules governing your enemy. More rules usually means more advanced artifical intelligence.

you could have a data structure (read: array) set up for each enemy, and then iterate through each data structure for each cycle of the main game loop, and apply some rules based on the data that exists for the enemies.

For example:

Data Structure:
Zeros(100)->GDB0
.+0=type of enemy
.+1=animation
.+2=X coordinate
.+4=Y coordinate
.+6=X velocity
.+8=Y velocity

You can have up to ten enemies in this example, and you'll have to load up code for each enemy by hand, or write a program to do it for you, or make it part of your tilemapper.

After you have the data structure, you would have as a part of your main game loop:


For(A,0,9)

.add XVelo to XCo and YVelo to YCo
{A*10+GDB0+6}r+{A*10+GDB0+2)r->{A*10+GDB0+2}r
{A*10+GDB0+8}r+{A*10+GDB0+4)r->{A*10+GDB0+4}r

If {A*10+GDB0}=0
.do some stuff based on the ruleset
.for what to do for type 0 enemies
ElseIf the type = 1
.do some stuff based on the ruleset
.for what to do for type 1 enemies
ElseIf the type = 2
.et cetera
Else
.you get the idea
End

End


Where r is the little superscript r thing.

And then, you would just have a display function that displayed the enemies at their X and Y coordinates with whatever animation crap you wanted.


Some example rules you can implement (all implemented in the form of if statements)

If enemy touches player
decrease player's health

If enemy is to the left of player
move enemy to the right

If enemy is to the right of player
move enemy to the left

If the enemy hits an object
make it go in the opposite direction


Et cetera et cetera et cetera.