OK, i took the plunge. bought this AND space out from binarysquare.
Spinblox is
very nice. The gameplay is a mix of panel de pon, bejeweled and lumines (but with no musical element to it before you get too excited

. you slide colored blocks left, right, up and down to form same color lines of 3 or longer. you can also make crosses and other shapes combining the same colors.
The lumines aspect is in how the block are cleared. They don't disappear automatically but only when another timed wave of blocks comes in from the top. this allows you to set up combo chains in advance (if you're good - I'm not. I can never set up complex chains in these types of puzzle games)
Advanced mode has powerup (or powerdown) blocks that need to be eliminated along with the 3 block patterns. These can clear all blocks of the same color or extend your time. It adds some spice to the formula but you can play without it and still enjoy the mechanics.
It's good. It's
real good. And for 5 bucks, you can't go wrong if you're into these kinds of puzzle games.
And the polish on the game is fantastic. the custom pixel graphics along the bottom of the screen; the selection of wallpapers that float by in the background. And the help manual is very nicely done. it's a multi page book that you swipe across. it's in full color with small pics and a little bit of teh funny.
And the binarysquare fanfare music that chimes in when you open the app is classic 8 bit nostalgia.
Space Out is simpler to grasp as it's basically Space Invaders where you use a breakout ball to destroy the ships instead of a missile. It controls well (there's space below the paddle for you to place your finger on the screen, so you can still see your paddle while moving - nice) and I never felt like the touch controls were unresponsive.
What makes this unique and potentially worth the 5 bucks over free alternatives is the retro art style and polish: The slick interlaced screen and classic graphics, the cool C64 sound effects and voice synth. It's also nice the way the edges of the screen flash white when the ball hits them.
I would recommend both to the GAF crowd but Spinblox is the standout game between the two.