Paying may suck
its true you have to pay to get the latest update, but look at the bright sides
1. its cheap (very cheap)
2.you have to pay for any normal game
3. you can still play the non updated version
and when they release the next update they will probably give you all the things from this update anyway.
But if you can't wait or can't Work then there are hundreds of others physics games out there for example "Phun" which i basically exactly like incredibots in fact its got all the promised updates that incredibots offered other then thrusters and boosters. but basically we can live. we liked it with out the updates and it basically the same.