This is an interesting prototype for Espial which was most
likely made for magazine reviewers. While the game itself is
the same as the final version, it still has some debug features
enabled. The left difficulty switch acts like a pause button
(A pauses, B unpauses) while the right difficulty switch is used
to turn the collision detection off and on. Both of features
would have been handy for reviewers who wanted to see all the
levels and pause the game for a screenshot.
If you look closely at the labels you can see that the word TI
is crossed out and VCS is written in. Either the EPROMs were
reused from the TI version of the game or the were accidentally
labeled as such.