PUSHOVER
==========

Pushover is a faithful reimplementation of the game with the same name published
in 1992 by Ocean. It contains the original levels. The graphics and sound are
very similar when compared with the original game.


Gameplay
----------

The task of the game is to rearrange the dominoes on the different platforms so
that you can start a chainreaction that makes all dominoes topple over. You may
rearrange all dominoes (except for one kind of domino) and place them wherever
suitable (except in front of a door).


You win the level, when:

- all dominoes (except for the blocker) have toppled
- no dominoes have crashed, they may fall off the screen though
- the trigger domino fell last
- and you reached the exit door within the time limit

The dominoes:

All in all there are 10 different types of dominoes:

- Standard, completely yellow. There is nothing special with this stone, it
  falls when pushed.
- Blocker, completely red. This domino can not fall over, so it is the only kind
  of stone that may still be standing when the level is solved. Dominoes falling
  against this stone will bounce back, if possible.
- Tumbler, big red stripe. This domino will stand up again after falling and
  will continue to tumble until it hits an obstacle or rests on another stone.
- Delay stone, diagonally divided. This domino will take some time until it
  falls, when it is pushed. Dominoes falling against this stone will bounce back
  and later this stone will fall.
- Splitter, horizontally divided. This stone will split into 2 stones, one
  falling to the left and the other falling to the right. The splitter can't
  be pushed. It must be split by a stone falling onto it from above. A pile of
  rubbish falling into it also activates this domino.
- Exploder, vertically divided. This stone will blast a gap into the platform it
  is standing on, when it is pushed. Neither the ant nor the pushing domino are
  harmed by that, the pushing domino will fall into the gap.
- Bridger, 1 horizontal strip. The bridger will try to connect the edge it is
  standing on with the next edge, if it is close enough, if not it will simply
  fall into the gap.
- Vanisher, 2 horizontal strips. The Vanisher will disappear as soon as it lies
  flat on the ground. This is the only stone you may place in front of doors.
- Trigger, 3 horizontal strips. This stone will open the exit door, as soon as
  it lies completely flat and all other conditions are met (see above). This is
  the only stone that you may not move around.
- Ascender, vertical strip. This stone will start to rise as soon as it is
  pushed. It will rise until is hits the ceiling, then it will start to flip
  into the direction it was initially pushed. When you fall into a gap while
  holding this stone it will also rise and stay at the ceiling until pushed.

Controls

The ant is controlled using the cursor keys and space. Use the space key to pick
up the domino behind the ant or to place it down where you are currently
standing. To push press first up to let the ant enter the row of dominoes. Then
simultaniously press space and either left or right cursor key depending on
whether you want to push the domino to your left or your right.

Hints

If you don't know where to start in a level, simply push a stone and observe
what happens. This helps very often to get a general idea how to solve a level
and where the problem is.

If you forgot which domino has what kind of special property press F1 to get a
short help. This window also displays a short hint, once the time of the level
is out.

The first few levels introduce you to the dominoes. Here you can explore how
the different dominoes behave in different situations.


Files
-------

Pushover places a few files on your hard-disc in everyday running. Those files
will be placed in your home directory. This directory is in

-  My Documents\Pushover    on Windows systems
-  ~/.pushover              on Unix systems

The following files are saved:

- solved.txt: This file contains checksums of all the levels that you have
  successfully solved. In the level selection dialogue those levels contain a
  mark. If you loose this file those marks are gone.
- *.rec: These files contain recordings of activities within a level. They are
  automatically created whenever you solve a level but you can also actively
  make a recording by pressing 'r' while you play a level. When you observe
  something strange while playing, make a recording and send it to me. Also when
  the game crashes a recording will be saved.  You can delete these files
  whenever you want. You can distinguish the recordings by the prefix in their
  name. "Sol" stands for solved levels, "Man" for manually created recordings
  and "Err" for recordings made when the program crashed.


Graphics
----------

Right now Pushover uses scaled versions of the graphics of the original game.
You are very much invited to improve those graphics. Please contact me if you
are interested so that I can tell you what the state of affairs is. But I will
tell here the basics

I have already replaced the dominoes with new graphics, but the graphics for the
ant and the background themes still need improvement.

The backgrounds are made out of 20x13 tiles. Each tile has a size of 40x48
pixel. The reason for that is the non square pixel of the 320x200 resolution of
the original game. For each theme there is a PNG image file containing all the
blocks that may be used by the levels. To make it possible to place the blocks
more freely into the PNG file a LUA file accompanies the image. This LUA file
contains the block positions of all the used blocks. Right now all the blocks
are one below another so the LUA files contain ever increasing y positions and
always the same x position.

It is already implemented to use transparency within the blocks. All the
existing levels use just one layer and thus need completely opaque tiles. But
many of those tiles could be separated into a stack of different tiles. This
then means the level need to be updated to actually use a stack of tiles instead
of just one. Right now we are limited to 8 layers, but if necessary this can be
made dynamic.

It is also planned to have something like animated tiles, but they have to be
kept at a low count. Not too many frames and not too many animations. They are
not intended to make the background dynamic, but to rather be a little finishing
touch to the graphics. Possibilities are trees that move from time to time in a
breeze, a bird that sails through the sky from time to time....

The ant is more complicated. The image ant.png contains all possible animation
images for the ant, one animation below the other. I have an additional GIMP
image that contains in separate layers possible surroundings of the ant in
different animation frames (like ladders, steps, ground, a carried domino...). I
will happily provide that image to the interested artist.


Level Designers
-----------------

Pushover will eventually get a level editor, but right now it hasn't, please be
patient.

But here are already some rules that you have to adhere to if you want your
levels included into the program

- They need to be put under the GPL licence, or something compatible. Otherwise
  inclusion is legally not possible. Copyright stays with you, of course.
- Please only contribute complete sets and no single levels. They don't need to
  be long, 10 levels is enough but this way you can keep up a constant scheme and
  theme logic of the levels.
- You absolutely _must_ provide a recording of one possible solution to each
  level. That solution is not within the distribution, just within the source
  code repository. It is used to ensure that the solution of your level is still
  possible after we made changes to the program. This way we limit possible
  frustration.
- Do only send non-compressed level sets. We need those for the inclusion in the
  source. And we need those for possible future updates.
- Use the index file to reorder levels, don't rename the files. This way
  inserting a level becomes very easy.
- You must not have more than one animated tile per level background.


Credits
---------

My thanks go to the original developers of the game. .....