How do we start playing?

This game is more of a prototype than a complete game! Unlike the trailer and the screenshots in the store page, I don't see any HUD including the meter bars at the top and bottom (life?) and the number of coins. It is impossible to pick up what I assume are weapons, you just go over them... It looks like there are only two short levels, at the end of level 2, the screen just stops scrolling and no more enemies appear... A seemingly broken single achievement (from its na...