The reason you can't get over the cars is because you aren't supposed to. Like in real life, you're supposed to walk *around* them. If you double-tap space and the right arrow at the same time, you can walk in front of some objects.
I ran into the same problem as Dragonforce: I killed everyone in every level, as well as scavenged every crate, but I couldn't get my level high enough to get through the gate...so I can't progress.
PsyRatty, the only one I know of (other than the two you mentioned) is to get the Megaton Laser and Double fire: this gives you Double Megaton Lasers, which is very nice.
I'm quitting at level 11. Unlike other puzzle games, I can't beat it even though I know a few solutions. Unlike other platformers, I don't feel like I'm getting any closer to success after subsequent tries.
If that level was tweaked slightly to be a little more forgiving, then this game would be a 5/5.
The column level is flat-out broken. On insane mode, it will randomly put up an actual wall (the top and bottom columns are actually touching) that is impossible to pass. This has happened to me about one in three tries so far.
Deus Ex Machina is used properly; you died, but the time machine uses the magic of plot holes to undo your death.
Also, what glitches are you guys talking about?
For some reason, I can't rotate the jet/prop engines. I could for the first few levels after they're introduced, then I suddenly couldn't...that makes it pretty well unplayable :(
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