It would be near impossible to translate a beatmap into something for this game. From the looks of the video, the main part of that game is the design for the way the patterns fly around/into the screen. Something like that can't be generically created from the information stored in a beatmap.
If you take away the patterns, then this is no different from DDR/SM/etc.
Maybe the relative directions and distances between notes can determine the patterns of the "beats"?
Longer distances may have larger notes (making the map harder to time and read, similar to making things a bit harder in standard). Direction can be angle information mapped to 90 degrees, which then show the direction the note comes to the bar. (E.g. zig-zag at 45 degrees would cause notes to come from 45 to 135 degrees alternating. Hope I'm explaining this right. =X)
I think spinners should have you "spin" using the keys. E.g. up, right, down, left and left, up, right down are valid orders for a spinner. I would guess the number of correct presses would equal half the number of presses required for a Taiko spinner?
I think you should come up with an exact algorithm (pseudocode or otherwise) for translating osu beats into these flying beats.
You haven't addressed things such as which side of the screen the notes should fly in from (it's not always the side closest to the direction you're supposed to hit) and how to recreate the way notes fly (eg. spirals before hitting, notes that change velocity, etc.), things that I feel are extremely important to this game.
Divide the screen into a grid and assign a different set of predetermined parameters into each grid square. The direction, wave type, and the speed of the objects, and other parameters could be determined by the square that the hit circle is positioned on the beatmap.
A number of different grids could be created with their own parameters assigned to them, and the total score for all of the above beatmap parameters (4+4+4+1+1 = 14) could determine which of the grids is used on the beatmap. And the colour of the hit circle, sounds, etc, could toggle between additional/extended grid parameters, such as effects, and so on.
An example of some parameters in a single grid square:
Object speed = 4 Wave type = ZigZag C Acceleration = 2.5 Direction Angle = 35 degrees Chaos = 17% Trail effect = 2
This method could also work well with any other future game modes.