The theme for the TriJam145 is 

There is a twist...!

Our twist is you can't see anything without movement due to how the brain processes visual's, the shapes only exist in your mind. Unfortunately that doesn't make for good screen shots, so please give it a spin to see how it works.

Game Play

This is a pretty basic platformer double jump some basic enemies and something to collect. But the twist is you can't see anything until it's moving. Screen shots would be pretty pointless as you would see nothing in them :D.

Play it and please if you get a headache or your eyes hurt do stop, I have absolutely no idea how playing this might effect some folks.

Idea

For some time I have wanted to build a game that used some sort of optical illusion or optical trick to make it. I decide to use an aspect of vision and shape recognition that relies on pieces moving together to create shapes. So no outlines just noise that is fixed to solid pieces and visible when moving.

You can read more about how the brain identifies and holds shapes once they stop moving in the link below. You might notice as the scrolling stops the shapes are almost perceivable for a while and fade. That is described in detail in the linked PDF although this original realization of how movement is identified as shapes dates back a lot further.

https://www.researchgate.net/publication/10699140_The_Lateral_Occipital_Complex_...

Development Time

Since this is a 3h jam here is my time spend on things.

Fri 15:30-16:00 (30m) Build tool to and convert all sprite to dot's

Fri 16:10-16:45 (25m) Build initial prototype and test (pretty happy with the results)

Fri 17:15-17:30 (15m) Add monster sprite

Fri 17:30-17:40 (10m) Added Star for collecting

Fri 17:45-18:45 (60m) Build level

Fri 18:45-19:00 (15m) Create stars UI and logic for collection

Fri 19:35-20:00 (25m) Build menu and win loose conditions, polish as much as I can :p

I wish I had time to have added some sound effects I think that would have been the most important addition. Although I am really curious how well particle effects would have been identifiable in the graphics system too.

I hope you enjoy playing and it doesn't give you a nasty headache.