At the start of each level the screen is clear except for a single ball with a star on it. Almost immediately, white balls start appearing in random locations with random velocities. Your only channel of interaction is through the star ball – click it and pull back to set your velocity vector and release to set it in motion. Colliding with a white ball will change it into a black one. When two black balls collide, they annihilate each other, a point is earned, and a red ball appears at the opposite point on the screen. A collision between red balls is worth two points because you cannot touch them directly with the star ball, you must go through a black ball, much like shooting through balls in pool. Green balls, the last and rarest type of ball, render you invincible for 5 seconds, and any ball you touch in that time disappears and gives you one point. Each of the ten levels gives you a set amount of time to earn a certain number of points.
Analysis: I must admit, I'm a big fan of simple idea games – when the idea is strong enough to sustain complex, non-repetitive gameplay and stands up to multiple replays. The idea behind Rmvblls accomplishes this goal superbly... almost. By making a dangerous red ball appear for each pair of blacks eliminated, Eduardo forces you to plan your moves carefully rather than just spastically trying to go on a scoring spree. Essentially, he's making you clean up after yourself, or at least be very very careful in navigating through your mess.
The one thing holding Rmvblls back is not that it lacks anything, but rather that it has one color too many. The green balls offer so much of a scoring advantage that it's easier just to wait for a bunch of white balls and one green ball to appear, then go on a five-second rampage, gaining huge amounts of points without having to worry about littering your screen with red balls.
It's a common decision that game designers face: Do you start to introduce powerups, or do you leave things simple? If you do add powerups, when do you stop? In the opinion of this casual gamer, you should either go all out (a la Areas) or keep them as minimal as possible to sustain a good game. In the case of Rmvblls, the green balls only served to detract from what was otherwise an expertly balanced and fun game.
Don't get me wrong – I love this game. There's nothing about it I found annoying or difficult, although some commenters did report problems with the edges of the Flash frame, so YMMV. Still, overall the game exhibits a good degree of polish. If anything, it resembled the previous contest winner just a tad too much, which may have lowered its score a touch, but in all other respects is an extremely good thing for a game to do.