diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..63265ca
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020 He4eT
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
index 92a5d38..f375b48 100644
--- a/README.md
+++ b/README.md
@@ -1,20 +1,31 @@
 # Yet another experiment 
 
+[![Play online](https://img.shields.io/badge/Play-online-orange?style=flat-square)](https://he4et.github.io/elseifplayer/#/focus/https%3A%2F%2Fifarchive.org%2Fif-archive%2Fgames%2Ftads%2Fyet_another_experiment.t3/toxin/)
+[![IFDB](https://img.shields.io/badge/IFDB-page-lightgrey?style=flat-square)](https://ifdb.tads.org/viewgame?id=rsssdo3anjpwnt6e)
+
 A small "escape the room" style [TADS3](https://www.tads.org/) game.  
 Designed as a set of examples for developing [interactive fiction](http://www.ifwiki.org/index.php/FAQ).
 
-![screenshot](/screenshot.png?raw=true)
+![screenshot](/docs/screenshot.png?raw=true)
 
 ## How to play
 
-1. Download the story-file on the [release page](https://github.com/He4eT/tads3_experiment/releases)
-1. Install the interpreter that supports TADS adventure games (see the list below)
+You can 
+[play this game online](https://he4et.github.io/elseifplayer/#/focus/https%3A%2F%2Fifarchive.org%2Fif-archive%2Fgames%2Ftads%2Fyet_another_experiment.t3/toxin/)
+or play it with any TADS3 interpreter.
 
-### List of interpreters
+See this [cheat sheet](http://pr-if.org/doc/play-if-card/play-if-card-300dpi.png) if you are not familiar with interactive fiction.
 
-  - Desktop: [gargoyle](https://github.com/garglk/garglk/) or [frobtads](https://github.com/realnc/frobtads)
-  - Android: [fabularium](https://play.google.com/store/apps/details?id=com.luxlunae.fabularium&hl=en)
-  - iOS: [frotz](https://apps.apple.com/au/app/frotz/id287653015)  
+### Play with an interpreter
+
+1. Download `yet_another_experiment.t3` from the [release page](https://github.com/He4eT/tads3_experiment/releases).
+1. Install the interpreter that supports TADS adventure games (see the list below).
+
+#### List of interpreters:
+  - Web: [elseifplayer](https://he4et.github.io/elseifplayer/#/);
+  - Desktop: [gargoyle](https://github.com/garglk/garglk/) or [frobtads](https://github.com/realnc/frobtads);
+  - Android: [fabularium](https://play.google.com/store/apps/details?id=com.luxlunae.fabularium&hl=en);
+  - iOS: [frotz](https://apps.apple.com/au/app/frotz/id287653015);
 
 See the [full list](http://www.ifwiki.org/index.php/Interpreter).
   
@@ -29,19 +40,19 @@ the full list of "bricks" on [this page](/docs/table_of_contents.md).
 
 ### Pre-build
 
-  1. Clone this repo
-  1. Install [frobtads](https://github.com/realnc/frobtads)
-  1. Copy `frobtads/tads3/lib/` to `project_path/lib/`
-  1. Copy `frobtads/tads3/include/`to `project_path/lib/include/`
+  1. Clone this repo;
+  1. Install [frobtads](https://github.com/realnc/frobtads);
+  1. Copy `frobtads/tads3/lib/` to `project_path/lib/`;
+  1. Copy `frobtads/tads3/include/` to `project_path/lib/include/`;
   
 ### Build
 ```
-t3make -f experiment
+t3make -f yet_another_experiment
 ```
 
 ### Incremental build
 ```
-watch -n 1 t3make -d -we -nobanner -f experiment
+watch -n 1 t3make -d -we -nobanner -f yet_another_experiment
 ```
 
 ## Tutorials and documentation
diff --git a/map.md b/docs/map.md
similarity index 100%
rename from map.md
rename to docs/map.md
diff --git a/screenshot.png b/docs/screenshot.png
similarity index 100%
rename from screenshot.png
rename to docs/screenshot.png
diff --git a/experiment.t b/experiment.t
index fe1a4bd..2ebe299 100644
--- a/experiment.t
+++ b/experiment.t
@@ -10,7 +10,8 @@ versionInfo: GameID
   showAbout () {
     " << desc >> <br>
       Designed as a small set of
-      useful examples for developers. ";
+      useful examples for developers.\b
+      https://github.com/He4eT/tads3_experiment/";
   }
 
   byline = 'by He4eT'
diff --git a/src/item/elevator.t b/src/item/elevator.t
index 16b729f..801a54f 100644
--- a/src/item/elevator.t
+++ b/src/item/elevator.t
@@ -18,10 +18,13 @@ elevatorDoor: LockableWithKey, Door
 
   dobjFor (UnlockWith) {
     action () {
-      inherited;
-      self.makeOpen(true);
-      " A few seconds later
-        the elevator arrived on the floor. ";
+      if (keyFitsLock(gIobj)) {
+        self.makeOpen(true);
+        " A few seconds later
+          the elevator arrived on the floor. ";
+      } else {
+        " You can't apply this to a card reader. ";
+      }
     }
   }
 
diff --git a/test/unlockElevatorWithWrongKey b/test/unlockElevatorWithWrongKey
new file mode 100644
index 0000000..fa039ec
--- /dev/null
+++ b/test/unlockElevatorWithWrongKey
@@ -0,0 +1,13 @@
+>turn on the light
+>w
+>open locker
+>take floss
+>e
+>s
+>s
+>take tape
+>w
+>open dumpster
+>search cloth
+>take key
+>unlock elevator with tubular key
diff --git a/test/walkthrough b/test/walkthrough
new file mode 100644
index 0000000..16ff09b
--- /dev/null
+++ b/test/walkthrough
@@ -0,0 +1,33 @@
+>turn on the light
+>w
+>open locker
+>take floss
+>e
+>s
+>s
+>take tape
+>w
+>open dumpster
+>take cloth
+>search cloth
+>take key
+>e
+>unlock door
+>e
+>x assistant
+>x cable
+>x connector
+>fix connector with floss
+>plug cable in robot
+>x robot
+>a team
+>a Alice
+>w
+>w
+>type 1984 on keypad
+>x middle locker
+>take keycard
+>unlock elevator with the keycard
+>s
+>e
+>q