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Great fun but way to hard.
The first level is simple... the second one is ok... but the fifth! Even with the generous 20 lives I couldn't get past it. I expect the 40th level to require a zen like mastery of space and time. The music needs some work but the grafics and sound effects are decent. Just turn off the music and play your favourite tunes in iTune in the background.
Pros: Simple and fun
Nice physics model
Cons: Bad music
Very hard