Selecting an option to set accelerate along a vector should never require additional scripting. If gravity is wanted in a game, then a construct of 'gravity' (accelerate/vector) would already be an inherent part of an engine's abilities, and developers using that engine should only have to add the variable to a player or not. From there, if specific additional functions surrounding the effect of gravity are wanted, scripting can be considered. I maintain (and UE1 through UE4 validates this) the following interactivity points can be used to make about ninety five percent of all games out there, regarding interactive function, and would simply require a tick field for each (maybe a 'select other object' field) to get nearly anything done that's wanted:
gravity (vector move)
collision
move
jump
crouch
triggerEvent
spawnObject
destroyObject
fireWeapon
pickUp/carry
damage
health
targetObject
HUD
None of this includes rendering functions, level object placement or audio access of course: all of that will be deeper API coding, from what I experienced looking over the shoulder of Dave Hagewood, Tim Sweeney, Steven Polge, Laurent Delayen and Per Vorgensen when I worked at Epic. I've worked directly beside programmers my entire professional career and had extensive discussions over each of these guys about the approaches used and why. None of the interactivity above is new. It is standard from the times of the Atari 2600 and is a travesty that game engines today for the most part don't have these as some kind of drop-down module with a few settings, all of which could be extended via script if needed.
But a few people got it right, and they drive around in Lamborghinis.
Just a suggestion to the guys here...make GUIS for these standard gameplay aspects and your engine will shoot past all the others which only cater to programming. Don't get me wrong: I have nothing against programming or programmers. Indeed, I'd give anything to be able to pay a team of super experienced and capable programmers to create a game engine under the guidelines above, because almost all the questions I see on this forum, and Unity forums, and GameMaker forums are about these common things.