Occasionally, a game may appear on both of these lists. One of the very first to do so was Tyler Glaiel's Magnetism, primarily because it contains 100(!) levels of ball-bouncing, magnetic field-inducing madness. Now, Vadim Ledyaev channels the spirit of Magnetism with Trigger Ball.
Complete a level by bumping each black orb with a smaller black ball, which is launched with a click of the mouse. You only get one shot, so use it wisely! Use your mouse to set the trajectory, and use [left] arrow and [right] arrow to adjust your starting position, if you are allowed that luxury. A check-mark will appear on each orb after it's been struck, but another hit will take it away, and all orbs must be checked before the level is complete! Trigger Ball is more than just a game of angles though, as you'll find yourself dealing with centers of magnetism, both attractive and repulsive. Later levels also add moving targets, as well as moving magnets. Scoring is a bit unusual—you earn points equal to the number of the level, but you lose one point for each shot you take. This equates to a kind of convoluted way of keeping track of the number of shots, but it works. Presumably, you lose the game if you run out of points, but the beginning levels are so easy that this becomes a non-issue.
Ever since Magnetism (and probably before, too), the concept of using attractors to guide an object to some goal has been used numerous times, and despite having a different goal and a somewhat unique launch method, Trigger Ball feels much the same as these other games—not that there's anything wrong with that. I must admit, despite my affinity for strategy games and games that put the user in control of as many aspects as possible, there's a certain pleasure to be had in just letting go and placing yourself at the whim of gravity. On the other hand, some levels here take this concept to an extreme—sometimes you can walk away from the computer, prepare the caffeinated beverage of your choice, and return to find that ball still whizzing around the unpassed level.
The level design in Trigger Ball tends toward the simplistic. Everything—balls, orbs, magnets—is circular, which both unifies and limits the game. Collisions between convex surfaces magnify differences in trajectory, thus making it harder to find that sweet spot that wins the level. Although it would add a small amount of clutter, I'd like to see more variance in the shapes and collisional properties of the goals and obstacles. Or maybe it's just the night-owl in me pining for a more Magnetism-like experience; after all, with just 41 levels, Trigger Ball isn't likely to keep anyone playing long into the wee hours. But I bet you'll wish it did.