I’m not sure I’m seeing what is supposed to be seen.
Tried several modes (2D, crossed, anaglyph) and visually I’m going backward, not forward. And all collectibles and avoidables appear behind my back, then fly next to me and disappear somewhere ahead of me.
In other words, the tunnel does not come to me, but goes away of me.
The direction is OK now. I played it a bit. It looks fun. Here are some observations and ideas:
the bad guys are just hovering, I’d have expected they are more aggressive
at every 1km boundary the motion becomes very fast for 3-4 seconds
I have the impression that parallel and crossed eyes are swapped, i.e. i played with my eyes crossed, but the 3D was seen in parallel mode (on crossed eyes mode there was no depth effect)
sometimes the ship and the panel attached to it make it difficult to see the obstacles ahead
you may introduce more enemies (e.g. one with tentacles, one one spitting ink that blinds you temporarily, etc.)
you may add some change in the tunnel (apart from its texture), e.g. sharper turns, narrow sections, tunnel splitting, etc.