I like the concept. Laying the controls out a little better would help. Also having upgrades to the magnets and the city would be awesome. Making bigger rocks would also keep it challenging, but overall not a bad start.
The controls are really awkward. WASD do not map well to the four corners. Maybe the numpad would have been better? The idea was intriguing enough to get me to play. You just need to refine it quite a bit.
This game needs more work on the controls and gravity physics.
the controls dont work.
may want to fix it.
Needs lots of work
Neat idea and done well as far as it goes, but it really needs lots of work.
Work on the graphics and interface, that's a big one.
But then you need to add some new stuff. Have the rocks crash into each other would be good, because you could then add non-magnetic rocks and crash bonuses and fun stuff like that.
And a power-up system - something to actually aim for and keep people playing beyond the second wave.