Proper player speed

[ForNeVeR]

For now, the player movement model is the following:

• we have three levels of engine power for both X and Y axis
• each power grants 1 px per tick movement
• both X and Y are independent, so you can move by 3x+3y max per tick

While this resembles the original, I'm not sure how accurate it is. Please measure the original game speed (I use OBS + MPC-HC to track concrete frames) and make sure our rules are the same as in the original.

[ForNeVeR]

I've just played original, and apparently there are 5 horizontal and 4 vertical speed levels there!