Even though all games could be said to need motor skill in some way, there definitely is a big difference how much of the game relies on motor skill and how much on other cognitive functions.

You can easily check the distribution by imagining your game being played by someone with severe neurological damage (like a broken neck), and thus having severely limited motor response.

That usually means at best being able to select and click something on a screen, perhaps dragging a little with bad precision.

How well will he/she do?

(Side note: There is currently at least one "game" being played by monkeys using nothing but neural interface directly into the brain, that does though hook into the motor cortex, and the monkey needs to learn to use it like any other limb. So I'd say even that needs motor skill)

• Alertness (ability to notice something when it occurs/exists)
• Sustained attention (ability to maintain concentration on a particular activity)
• Selective attention (ability to filter out irrelevant information)
• Divided attention (ability to focus on more than one thing)
• Visualization (ability to picture something in the mind even if it's not there)
• Foresight (visualizing future states of play, planning future moves)
• Recall
• Spatial reasoning
• Inhibition (ability to avoid potentially unwise impulses)
• Flexibility (ability to "switch gears" to another activity)
• Creativity (ability to generate novel inputs or solutions that you have not encountered before)
• Motor planning (ability to put together a script for future motor action)
• Reaction (ability to carry out a motor plan in response to a stimulus)

I would say your game primarily tests spatial reasoning (specifically, judging angles) and reaction (acting when the moment is appropriate).

Alertness (because you have to be observant of a changing angle) and foresight (because you actually have to put your motor plan into action slightly before the angle is right) are important, too, but because the angular motion is pretty predictable they're not required to a greater degree than in your average action game. Likewise, pretty much every action game is going to require sustained attention and motor planning; this does too but not in a notable or unusually complex way.

So just to play with the typology a bit, your game tests pretty much the same skills as the core loop in a golfing game. (Not surprisingly!) Comparing it to the standard "fishing minigame" (like in Zeldas, or Torchlight), the fishing game doesn't so much test spatial reasoning, but is much more focused around alertness (because the movement you have to be watching isn't as predictable; you can't let your attention wander for even a moment). On the other hand, a fighting game likewise tests spatial reasoning, reaction, etc., but also involves queuing up non-trivial motor plans, complex series of motor movements to be unleashed at the right moment/place. (Among many other skills, of course.)

Anyway, hope this helps!

So once I tried to brainstorm some of the cognitive skills that were relevant to games, and I just found the list. Maybe it'll be of use to you. But note that these aren't all meant to be "official" or "scientific" terms.

• Alertness (ability to notice something when it occurs/exists)
• Sustained attention (ability to maintain concentration on a particular activity)
• Selective attention (ability to filter out irrelevant information)
• Divided attention (ability to focus on more than one thing)
• Visualization (ability to picture something in the mind even if it's not there)
• Foresight (visualizing future states of play, planning future moves)
• Recall
• Spatial reasoning
• Inhibition (ability to avoid potentially unwise impulses)
• Flexibility (ability to "switch gears" to another activity)
• Creativity (ability to generate novel inputs or solutions that you have not encountered before)
• Motor planning (ability to put together a script for future motor action)
• Reaction (ability to carry out a motor plan in response to a stimulus)

I would say your game primarily tests spatial reasoning (specifically, judging angles) and reaction (acting when the moment is appropriate).

Alertness (because you have to be observant of a changing angle) and foresight (because you actually have to put your motor plan into action slightly before the angle is right) are important, too, but because the angular motion is pretty predictable they're not required to a greater degree than in your average action game. Likewise, pretty much every action game is going to require sustained attention and motor planning; this does too but not in a notable or unusually complex way.

So just to play with the typology a bit, your game tests pretty much the same skills as the core loop in a golfing game. (Not surprisingly!) Comparing it to the standard "fishing minigame" (like in Zeldas, or Torchlight), the fishing game doesn't so much test spatial reasoning, but is much more focused around alertness (because the movement you have to be watching isn't as predictable; you can't let your attention wander for even a moment). On the other hand, a fighting game likewise tests spatial reasoning, reaction, etc., but also involves queuing up non-trivial motor plans, complex series of motor movements to be unleashed at the right moment/place. (Among many other skills, of course.)

Anyway, hope this helps!

Wonderful! Thanks so much for the answer, this is along the lines of what I was looking for. Now to review and construct a list of my own! (Unless It turns out yours is perfect XD).