no, that's not flash.
Ah, I see. In that case I'll see if I can get the Windows executable to run under Wine. Thanks!
Linux version available as of today. ;)
Edit: I successfully ran the game in Ubuntu 17.10.
There is a bug which is triggered when the game is run on a screen with multiple monitors, at least in my window manager (Fluxbox) and with my monitor layout (where the primary monitor on which the game is fullscreened is an external monitor larger than the laptop screen). The screen geometry is not calculated correctly, and the game screen is displayed oddly resized within the fullscreened window. Additionally, the game does not detect the position of the mouse cursor correctly -- everything is offset.
My initial workaround was to disable the external monitor. I then disabled fullscreen before I exited the game, and when I launched it again (with the monitor re-enabled) it remembered the fullscreen preference but the other issues were still present (in the non-fullscreened window). However, after playing around with the window I found that manually resizing the window causes everything to be redrawn correctly, and fixes all the issues. It is then also possible to fullscreen the game on the external monitor correctly.
For any other Linux users encountering the same issue:
1. F11 to exit fullscreen if necessary
2. alt-drag the window until you get to a corner or to the maximise button
3. Resize the window by dragging the corner or maximising. Now everything should be rendered correctly.
4. Now you should be able to resize the window however you like, or fullscreen it again with F11.
You may need to do this every time you launch the game, but you may be able to use the features of your window manager to automatically resize the window for you on launch. That is completely dependent on your environment. For example, in Fluxbox you can choose to remember various window properties, and this allowed me to create a persistent solution.