In level 19, instead of following the walkthrough, we can put the second slicer at the position above the entrance, and attach a blue linker, a green fork, a blue optimizer and a red range to it. It works wonderfully, as the linker can redirect the beam ray at good angles.
I found a good strategy to upgrade. Firstly, do the upgrade while playing by pressing ESC once you got enough upgrade points. Secondly, upgrade the boomerage/bomb first, then darts/laser, then tentacles. (Except for the final upgrade, where you upgrade the tentacle first, then bomb, and DO NOT upgrade the final laser as it is actually weaker than the three-way small laser.) This way you will easily have over 130000 points.
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