I've never tried making a text adventure before so I thought I'd give it a go.
This was originally supposed to be 20 lines, but it's not
disable systemkeys
disable escapekey
hide mouse
sync on
`Create World Map (water=0 : grass=1 : town=2 : woods=3 : cave=4)
DIM map(4,4)
map(0,0)=0 : map(1,0)=1 : map(2,0)=1 : map(3,0)=3 : map(4,0)=4
map(0,1)=0 : map(1,1)=2 : map(2,1)=2 : map(3,1)=3 : map(4,1)=3
map(0,2)=2 : map(1,2)=2 : map(2,2)=2 : map(3,2)=1 : map(4,2)=1
map(0,3)=1 : map(1,3)=1 : map(2,3)=3 : map(3,3)=3 : map(4,3)=0
map(0,4)=0 : map(1,4)=3 : map(2,4)=3 : map(3,4)=3 : map(4,4)=0
`Create Player
DIM Pstat(5)
Pstat(0)=1 : `fighting
Pstat(1)=0 : `weapon
Pstat(2)=0 : `magic
Pstat(3)=0 : `spell
Pstat(4)=30 : `HPmax
Pstat(5)=Pstat(4) : `HP
Px=1 : Py=1 : `player start position
slot=0
item=0
item$=""
action$=""
EnemyHP = 0
EnemyFight# = 0.0
randomize timer()
`--------------------------
` MAIN PROGRAM
`--------------------------
REPEAT
cls
print "Map Reference: "; Px; ", "; Py
if Py-1>=0 then print "To the NORTH is the "; ~map_info(map(Px,Py-1)) : `North
if Px+1<=4 then print "To the EAST is the "; ~map_info(map(Px+1,Py)) : `East
if Py+1<=4 then print "To the SOUTH is the "; ~map_info(map(Px,Py+1)) : `South
if Px-1>=0 then print "To the WEST is the "; ~map_info(map(Px-1,Py)) : `West
print
print "You are standing in the "; ~map_info(map(Px,Py)) : `Location
If action$ <> "" then cls : Print action$
input "> "; com$ : gosub command
If action$ <> "" then cls : Print action$ : wait key
if item=0 then action$=""
sync
UNTIL close=1
undim map(4,4)
undim Pstat(5)
END
`--------------------------
` FUNCTIONS
`--------------------------
FUNCTION ~map_info(tile)
SELECT tile
case 0 : tile$="sea" : endcase
case 1 : tile$="grassland" : endcase
case 2 : tile$="town" : endcase
case 3 : tile$="forest" : endcase
case 4 : tile$="cave" : endcase
ENDSELECT
ENDFUNCTION tile$
`--------------------------
` GOSUBS
`--------------------------
command:
SELECT upper$(com$)
Case "NORTH"
If Py-1>=0
If Map(Px,Py-1)>0 then Py=Py-1 : item=0 else action$ = "You can't swim."
else
action$ = "You can't travel there."
endif
Endcase
Case "EAST"
If Px+1<=4
If Map(Px+1,Py)>0 then Px=Px+1 : item=0 : else action$ = "You can't swim."
else
action$ = "You can't travel there."
endif
Endcase
Case "SOUTH"
If Py+1<=4
If Map(Px,Py+1)>0 then Py=Py+1 : item=0 else action$ = "You can't swim."
else
action$ = "You can't travel there."
endif
Endcase
Case "WEST"
If Px-1>=0
If Map(Px-1,Py)>0 then Px=Px-1 : item=0 else action$ = "You can't swim."
else
action$ = "You can't travel there."
endif
Endcase
Case "SEARCH"
if rnd(3)=0
gosub get_item
action$ = "You found a level "+str$(item_pts)+" "+item$+". "
if Pstat(slot) >0 then action$ = action$+"You already have a level "+str$(Pstat(slot))+" "+item$+", taking this one will replace it."
else
action$ = "You find nothing of interest."
endif
Endcase
Case "ACCEPT"
if item>0
action$ = "You took the "+item$+"."
Pstat(slot) = item_pts
item=0 : item_pts=0 : slot=0 : item$=""
else
action$ = "There is nothing to take."
endif
Endcase
Case "STATS" : action$ = "PLAYER STATS: Fighting: "+str$(Pstat(0))+" Weapon: "+str$(Pstat(1))+" Magic: "+str$(Pstat(2))+" Spell: "+str$(Pstat(3))+" HP Max: "+str$(Pstat(4))+" HP: "+str$(Pstat(5)) : endcase
Case "EXIT" : close=1 : endcase
Case "" : endcase
Case Default : action$ = "OUCH!! You could have someone's eye out with your typing! (Command not understood)" : endcase
ENDSELECT
RETURN
get_item:
item=rnd(1)+1
SELECT item
Case 1 : item$="WEAPON" : slot=1 : Endcase
Case 2 : item$="SPELL" : slot=3 : Endcase
` Case 2 : item$="HP POTION" : slot=5 : Endcase
ENDSELECT
item_pts = rnd(9)+1
RETURN
Map:

Key:- Orange=Town, Blue=Water, Green=Grassland, DarkGreen=Forest, Grey=Cave
Commands:
NORTH, EAST, SOUTH, WEST - move in specified direction.
SEARCH - search area for items.
ACCEPT - take item.
STATS - view your character's statistics.
EXIT - exit the game.
Coming Soon...

Monsters to battle

People to talk to. They may help you or challenge you!
[EDIT]
I've corrected some errors in the program. Everything I've made so far should work. Please leave me your comments and any bugs.
I'm going to re-write this anyway because it's getting messy
Your signature has been erased by a mod because it was rubbish.