diff --git a/chameleonic.p8 b/chameleonic.p8
index a825aa9..83aaa5b 100644
--- a/chameleonic.p8
+++ b/chameleonic.p8
@@ -117,7 +117,7 @@ function _rast(
  if (x0<x1) sx=1
  if (y0<y1) sy=1
 	
- local done=false,err
+ local done,err
  if dx>dy then
   err=dx/2.0
   while x0!=x1 do
@@ -252,8 +252,7 @@ end
 normpal = {[1]=0,[8]=0,[14]=0}
 pitpal = {[8]=0,[13]=3,[4]=3,[7]=3}
 function level:draw()
- fillp(0b1111111110111111)
- rectfill(0,0,127,127,0x55)
+ cls(5)
  fillp()
  pal(normpal)
  map(
@@ -289,7 +288,7 @@ function level:busy()
  for _,crate in pairs(self._crates) do
   if (#crate.todo>0) return true 
  end
- return false
+ return 
 end
 
 function level:update()
@@ -352,7 +351,7 @@ function level:recollide()
    local mxy=_mix(mx,my)
    self._coll[mxy]=
     fget(self:_mget(mx,my),7) or
-    self._crates[mxy]!=nil
+    self._crates[mxy]
   end
  end
 end
@@ -390,8 +389,7 @@ function level:reanchor()
   end
  end
 
- local anch_old=self._anch
- if (anch_old==nil) anch_old={}
+ local anch_old=self._anch or {}
  for _,old in pairs(anch_old) do
   old.dropped=true
  end
@@ -429,19 +427,18 @@ function level:anchor_points()
  keys=all(self._anch_keys)
  return function() 
   local k=keys()
-  if (k==nil) return nil
-  return self._anch[k.key]
+  if (k) return self._anch[k.key]
  end
 end
 
 function level:get_open_pit(mx,my)
  local pit=self._pits[_mix(mx,my)]
- if (pit and pit.contents==nil) return pit
+ if (pit and not pit.contents) return pit
 end
 
 function level:spawn_exit()
  self._wins={}
- local spawned=false
+ local spawned
  local spawn_at=function(x,y)
   if (self:_mget(x,y)!=1) return
   assert(not spawned,x..","..y) 
@@ -470,7 +467,7 @@ function level:spawn_exit()
 end
 
 function level:mcoll(mx,my)
- return self._coll[_mix(mx,my)]!=false
+ return self._coll[_mix(mx,my)]
 end
 
 function level:pcoll(px,py)
@@ -557,12 +554,12 @@ function level:can_move(
  if (is_player and self:win_at(mx1,my1)) return true 
  if (is_player and self:get_open_pit(mx1,my1)) return wrongbleep:adequately_warned()
 
- if (self:mcoll(mx1,my1) or player.x==mx1 and player.y==my1) return false
+ if (self:mcoll(mx1,my1) or player.x==mx1 and player.y==my1) return 
 
  if player.rope then
   local w,h=1.2,0.2
   if (dmx==0) w,h=0.2,1.2
-  if (player.rope:collide_mrect(mx0+ropecheck[dmx+2],my0+ropecheck[dmy+2],w,h,exclude_src,exclude_dst)) return false
+  if (player.rope:collide_mrect(mx0+ropecheck[dmx+2],my0+ropecheck[dmy+2],w,h,exclude_src,exclude_dst)) return 
  end
  
  return true
@@ -604,7 +601,7 @@ function player:reinit(x,y)
  self.px,self.py=0,0
  self.todo={}
  self.cooldown=4
- self.rope=nil
+ self.rope=nil  -- don't elide, needs to be cleared if present
 
  self.fall_frame=0
  
@@ -856,9 +853,9 @@ function rope:update()
   if (self.state.frame>=3) self.state={name="latched"}
 
  elseif self.state.name=="latched" then
-  if (self.latch==nil) wrongbleep:bleep(5) self:destroy() return
+  if (not self.latch) wrongbleep:bleep(5) self:destroy() return
 
-  if self.latch and self.latch.rec then
+  if self.latch.rec then
    self:drag_src(
     self.latch.rec.mx+0.5+self.latch.ax_offset,
     self.latch.rec.my+0.5+self.latch.ay_offset
@@ -920,7 +917,7 @@ end
 
 function rope:draw(artificial_px,artificial_py)
  local points,highlight=self:_tug(true)
- local n,perc_to_show,from_end = self.state.name,1.0,false
+ local n,perc_to_show,from_end = self.state.name,1.0
  if (n=="done") return
  if (n=="cast") perc_to_show=self.state.frame/2
  if (n=="destroy") perc_to_show=(1.0-self.state.frame/4)^2
@@ -1058,8 +1055,7 @@ end
 
 function rope:relax()
  local n0=self.src
- while true do
-  if (n0==nil) break
+ while n0 do
   if n0.associated_with and n0.associated_with.dropped then
    for i in level:anchor_points() do
     if i.ax==n0.ax and i.ay==n0.ay then
@@ -1075,26 +1071,25 @@ function rope:relax()
  local n0=self.src
  while true do
   local n1=n0.next
-  if (n1==nil) break
+  if (not n1) break
   local n2=n1.next
 
   if n0.ax==n1.ax and n0.ay==n1.ay then 
    n0.next=n2 
-   if (n2!=nil) n2.prev=n0
+   if (n2) n2.prev=n0
   else
    n0=n0.next
   end
  end
 
  local n0=self.src
- while true do
-  if (n0==nil) return
+ while n0 do
   local n1=n0.next
-  if (n1==nil) return
+  if (not n1) return
   local n2=n1.next
-  if (n2==nil) return
+  if (not n2) return
 
-  if n1.associated_with!=nil then
+  if n1.associated_with then
 
    local x0,y0=n0.ax,n0.ay
    local x1,y1=n1.ax,n1.ay
@@ -1130,7 +1125,7 @@ function rope:_check_sane()
  local qxs,qys={},{}
  while true do 
   local n1=n0.next
-  if (n1==nil) break 
+  if (not n1) break 
 
   _rast(qxs,qys,flr(n0.ax*2),flr(n0.ay*2),flr(n1.ax*2),flr(n1.ay*2)) 
   n0=n1
@@ -1152,21 +1147,21 @@ function rope:_check_sane()
  end
  local function _blocked(qx,qy)
   for i in all(_possible_tiles(qx,qy)) do
-   if (not level:mcoll(i.mx,i.my)) return false
+   if (not level:mcoll(i.mx,i.my)) return 
   end
   return true
  end
 
  -- find cases where i move through an impassable zone
  for i=1,#qxs do
-  if (_blocked(qxs[i],qys[i])) return false
+  if (_blocked(qxs[i],qys[i])) return 
  end
 
  -- find cases where i am cut off diagonally
  for i=3,#qxs do
   local qx1,qy1=qxs[i-1],qys[i-1]
   if qx1%2==0 and qy1%2==0 then
-   local ok=false
+   local ok
    for m0 in all(_possible_tiles(qxs[i-2],qys[i-2])) do
     for m2 in all(_possible_tiles(qxs[i],qys[i])) do
      local mx0,my0=m0.mx,m0.my
@@ -1183,7 +1178,7 @@ function rope:_check_sane()
     end
    end
 
-   if (not ok) return false
+   if (not ok) return 
   end
  end
  return true
@@ -1195,8 +1190,8 @@ function would_stick(x0,y0,anchor,x2,y2)
  local dx=x2-x0
  local dy=y2-y0
 
- if (x1==x0 and y1==y0) return false
- if (x1==x2 and y1==y2) return false
+ if (x1==x0 and y1==y0) return 
+ if (x1==x2 and y1==y2) return 
 
  local adx,ady
  local x1_new,y1_new
@@ -1255,8 +1250,6 @@ function rope:be_pushed_by(anchor,ax_old,ay_old)
     ny05=anchor.ay
     nx05=nx0+(ny05-ny0)/(ny1-ny0) * (nx1-nx0)
     -- printh("found (y): "..tostring({nx05,ny05}))
-   else
-    assert(false,"wtf?")
    end
 
    local n05={ax=nx05,ay=ny05,associated_with=anchor,prev=n0,next=n1}
@@ -1280,7 +1273,7 @@ function rope:_drag(n1,ax1_new,ay1_new,ax_removing,ay_removing)
     (anchor.ax==ax_removing and anchor.ay==ay_removing)
   end
 
-  if (ax_far0==ax_far1 and ay_far0==ay_far1) return nil
+  if (ax_far0==ax_far1 and ay_far0==ay_far1) return 
 
   if ax_far0==ax_far1 then
    local ax_far=ax_far0
@@ -1332,13 +1325,12 @@ function rope:_drag(n1,ax1_new,ay1_new,ax_removing,ay_removing)
  n1.ay=ay1_new
 
  local n0=n1.prev
- while true do
-  if (n0==nil) break
+ while n0 do
   local anch=_sweep_radar(
    n0.ax,n0.ay,n1.ax,n1.ay,
    n0.ax,n0.ay,ax1_old,ay1_old,ax1_new,ay1_new
    )
-  if (anch==nil) break
+  if (not anch) break
   local n05={ax=anch.ax,ay=anch.ay,associated_with=anch,prev=n0,next=n1}
   -- printh("creating pre: "..tostring(n0.associated_with).."->"..tostring(n05.associated_with).."->"..tostring(n1.associated_with))
   n0.next=n05
@@ -1347,13 +1339,12 @@ function rope:_drag(n1,ax1_new,ay1_new,ax_removing,ay_removing)
  end
 
  local n2=n1.next
- while true do
-  if (n2==nil) break
+ while n2 do
   local anch=_sweep_radar(
    n1.ax,n1.ay,n2.ax,n2.ay,
    n2.ax,n2.ay,ax1_old,ay1_old,ax1_new,ay1_new
   )
-  if (anch==nil) break
+  if (not anch) break
   local n15={ax=anch.ax,ay=anch.ay,associated_with=anch,prev=n1,next=n2}
   -- printh("creating post: "..tostring(n1.associated_with).."->"..tostring(n15.associated_with).."->"..tostring(n2.associated_with))
   n1.next=n15
@@ -1363,7 +1354,7 @@ function rope:_drag(n1,ax1_new,ay1_new,ax_removing,ay_removing)
 end
 
 function _stepfrom(x0,x1)
- local done=false
+ local done
  if x0==x1 then
   return function() 
    if (done) return
@@ -1378,12 +1369,12 @@ function _stepfrom(x0,x1)
  local i=flr(x0)
  local top=flr(x1)
  return function()
-  if (done) return nil
+  if (done) return 
   i+=1
   if i>top then 
    done = true
    if (x1!=flr(x1)) return mul*x1
-   return nil
+   return 
   end
   return mul*i
  end
@@ -1409,25 +1400,25 @@ function rope:collide_mrect(mx0,my0,mw,mh,exclude_src,exclude_dst)
 
  while true do
   local n1=n0.next
-  if (n1==nil) return false
+  if (not n1) return 
 
   local nd=n0
   for i=1,exclude_dst do 
    nd=nd.next
-   if (nd==nil) return false
+   if (not nd) return
   end
 
   local x1,y1,x2,y2=n0.ax,n0.ay,n1.ax,n1.ay
   local function _line_line(x3,y3,x4,y4)
-   local denom=((y4-y3)*(x2-x1)-(x4-x3)*(y2-y1))
+   local denom=(y4-y3)*(x2-x1)-(x4-x3)*(y2-y1)
 
    local ua=
     ((x4-x3)*(y1-y3)-(y4-y3)*(x1-x3))/denom
-   if (ua<0 or ua>1) return false
+   if (ua<0 or ua>1) return 
 
    local ub=
     ((x2-x1)*(y1-y3)-(y2-y1)*(x1-x3))/denom
-   if (ub<0 or ub>1) return false
+   if (ub<0 or ub>1) return
 
    return true
   end
@@ -1448,12 +1439,12 @@ function rope:tug_orientxy()
  local a1=self.dst
  local a0=self.dst.prev
  local dx=a0.ax-a1.ax
- local tdx=nil
+ local tdx
  if (dx>3/8) tdx=1
  if (dx<-3/8) tdx=-1
 
  local dy=a0.ay-a1.ay
- local tdy=nil
+ local tdy
  if abs(dy)>abs(dx)/2 then 
   if (dy>3/8) tdy=1
   if (dy<-3/8) tdy=-1
@@ -1494,11 +1485,11 @@ function rope:_tug(hypothetically)
  end
 
  local latch=self.latch
- if latch!=nil and latch.el=="eyehook" then
+ if latch and latch.el=="eyehook" then
   if (hypothetically) return ancs,0
   player.todo={{
    update=function(s) 
-    if s.rope==nil or s.rope:done() then
+    if not s.rope or s.rope:done() then
      return true
     end
    end
@@ -1506,7 +1497,7 @@ function rope:_tug(hypothetically)
   self:destroy(true)
   return true
  end
- if latch!=nil and latch.el=="crate" then
+ if latch and latch.el=="crate" then
   local dmx,dmy=
    sgn0(latch.dx),
    sgn0(latch.dy)
@@ -1522,7 +1513,7 @@ function rope:_tug(hypothetically)
   local mxa=(pull_anc.x+dmx)\8
   local mya=(pull_anc.y+dmy)\8
   
-  local invalid_move=false
+  local invalid_move
   if 
    (dmx!=0 and sgn0(pull_dx)!=dmx) or
    (dmy!=0 and sgn0(pull_dy)!=dmy) or
@@ -1546,15 +1537,15 @@ function rope:_tug(hypothetically)
   end
  end
 
- if (hypothetically) return ancs,nil
- return false
+ if (hypothetically) return ancs
+ return 
 end
 
 function rope:_calc_push(
  an,a0,a1,af
 )
  local ops={}
- if (an==nil) return ops
+ if (not an) return ops
 
  if a0.x==a1.x then
   -- no far side applying pressure?
@@ -1616,12 +1607,12 @@ function rope:_calc_push(
    -- great!
   else
    local crate=level:get_crate(o.mx,o.my)
-   if crate==nil then
-    break
-   else
+   if crate then
     if not level:can_move(false,o.mx,o.my,o.dmx,o.dmy,0,0) then
      break
     end
+   else
+    break
    end
    add(ops2,o)
   end
@@ -1636,7 +1627,7 @@ function rope:_anchors_simplified()
   return atan2(p1.y-p0.y,p1.x-p0.x)
  end
  a=self.src
- while a!=nil do
+ while a do
   local point={
    x=flr(a.ax*8+0.5),y=flr(a.ay*8+0.5),
    ax=a.ax,ay=a.ay
@@ -1646,13 +1637,13 @@ function rope:_anchors_simplified()
   if aw then
    if (aw.adx==1) point.x-=1
    if (aw.ady==1) point.y-=1
-  elseif a.prev==nil and l then
+  elseif not a.prev and l then
    if (l.ax_offset<0) point.x-=1
    if (l.ay_offset<0) point.y-=1
   end
 
   local p0,p1=points[#points-1],points[#points]
-  if p0==nil then
+  if not p0 then
    add(points,point)
   elseif _slope(p0,p1)==_slope(p1,point) then  -- epsilon?
    points[#points]=point