If you’re having trouble getting 400 seconds on Red, there’s a design “feature” that can help you rack up a few extra minutes in a fairly safe but rather boring fashion.
In the early game, try to pick up a shield (floating S) but do NOT collect any turret symbols (floating T). Eventually, the screen should start shaking and the first (and smallest) of the giagantic meteors will appear. The game won’t create any new meteors as long as there’s a giant meteor on-screen and careful juggling can easily keep the giant meteor onscreen for two minutes or more.
Turrets fire bursts that are too long and too uncontrollable, so they tend to send giant meteors off the left or right side of the screen fairly quickly. T symbols will appear as you juggle the giant meteor, though and they can be collected by a richoched shot.
It’s a very boring strategy-juggling would be insanely easy if there were no turret icons to avoid-but I used it to get a 500+ second score for the card challenge.
As for the Float part of the challenge, that’s fairly easy if you play it safe and emphasize control over aggressively grabbing yellow stars. Do make sure to grab the black ones immediately-they’re worth 20% of the goal score each-and flashing stars (20 seconds is a long time in this game)—and be sure to pick off as many yellow stars as you can safely.
