if(char.hitTest(ground)) {
char._y --;
while(char.hitTest(ground)) {
char._y --;
}
while(!char.hitTest(ground)) {
char._y++;
}
}

I assume you're running a while (!hitTestPoint) on the ground for both of the dots, right? When there's no ground underneath to hitTest, it just runs the loop to infinity. I think you could put<>
<>
if (char.y > 1000) { break; }<>
<>
right after the beginning of the while loop to prevent it. Then again it wouldn't fix anything, just prevent a complete crash.

Well, no, then your char will just be warping downwards indefinitely. Use a for loop instead of a while loop (never use whiles on anything that's !hitTest).

Use this to fix those extreme angles. Instead of adding 'speed' to _x, use this to add 'speed' to both, depending on the angle.

i still need to fix going up really fast for steep hills (also for the example, dont go off the edge, it screws flash up, just warning you)

I should have really read that before playing.

But seriously, it looks pretty good. I can't wait to see where you take that engine from here.

Also, you should fix the crash when you move to the extreme edges.

But, it's always good to know how to do it. So I'll explain the concept and you can apply it yourself in code.

First thing you need to do is apply the distance formula between the two points (character's "feet" ) and determine how far apart they actually are. Sqrt((x2-x1)^2+(y2-y1)^2) where (x1,y1) is the first pt, and (x2,y2)is the second pt. Subtract how far they are supposed to be from this number, then move each point by half of the extra distance.

here is an implementation similar to what I'm talking about. https://www.mochimedia.com/community/forum/topic/slope-detection

Since you know the position (coordinates) of the two points you use for slope detection, surely you can just detect the angle they make and apply the correct x and y coefficients to generate thrust for jumping.

If you apply the x,y thrust over time, you can also simulate gravity by letting the y thrust peter out until it's 0 then start going negative (obviously you should also apply a terminal velocity, otherwise you'll shoot through platforms). Then stop apply y thrust immediately when you detect a hit with a platform.