Now with art!

Crossing the flow

Help the animals to cross the flowing river!


No animals were decapitated during the making of this game
Presented by rdb

The "Moses of the Israelites" Award for Innovative use of Aquatic Obstacles
Presented by ntoll

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Ratings (show detail)

Overall: 3.2
Fun: 2.9
Production: 3.1
Innovation: 3.6

Respondents: 19


File Uploader Date
Game source
arifsch 2018/10/27 18:20
Now with art!
arifsch 2018/10/26 18:12
Crossing the flow
arifsch 2018/10/23 19:56
Flow field visualization
arifsch 2018/10/22 20:02
First day prototype
arifsch 2018/10/21 19:39

Diary Entries

First day

First day was mostly brainstorming a game idea fitting the theme. I came up with an idea of some sort of bridge building game, where the challenge is not the structural stability of the bridge, but the flow of the river during the build process.

Started prototyping a mass-spring system affected by some flow-forces using Pygame-Zero and NumPy.

First day prototype

Now let's see if I can make a game out of this...

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Flow field

Spent some time implementing the actual flow field, which is loaded from a map designed with Tiled and visualized with assets from . All nodes try to follow the flow field, unless fixed or limited by the connecting edges, which are simulated by a mass spring system.

Flow field visualization

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There is a goal!

Today I added agents that try to cross the river using the floating "bridge". And there is now also a winning condition. If all agents are in the target area, the level is complete. The objective will probably be to use as few segments for the bridge as possible.

Agents crossing the river to the yellow target area
Now, with the most basic gameplay working, a lot of polishing remains, i.e., adding scores, replacing the prototype art, add more levels, ...

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Fancy artwork

Back to work after a business trip. I have now finally added nice graphics courtesy of to replace the prototype renderer. Putting the graphics in allowed me to give this whole idea a theme. The first level now looks nice and I hope even plays well. The goal is to build a bridge of logs to help the animals get to the other side of the river. Let's see if I can add a few more levels tomorrow.

First level, now with nice graphics

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Final game uploaded

I've just uploaded the final game! Yay!

To play it, you need Python 3 (tested with 3.6 and 3.7), Pygame Zero and Numpy. If you've installed the dependencies, just unzip the source and run "python3" (see the README more more details).

Your goal is to help the animals to cross the river and reach the area with the large green tree.
To do so, build a bridge of logs, starting at the bare tree near the animals.

But you cannot place logs on land, only inside the water. Use the flow of the river to pull the bridge on land on the other side, so that the animals can cross the river.
Try to minimize the number of logs used!


  - Left mouse button: place new log, connected with the
                       highlighted points
  - Left/right key or mouse wheel: rotate log

Right now it contains just two levels (based on the same map). I would love to add more levels, but I haven't enough time for the final release.

I hope you enjoy it.