Space the clones against a wall
Jumping Clones moves every clone with the same key. Walk the group into a wall and the leading clone stops while the others catch up. In level 1, a held right arrow closes the gap between the 2 clones before any jump is needed.
Look before turning the room in Rotate
Q and E turn the whole room in Rotate, and the runner then stands on whichever surface has become the floor. Check that surface before pressing. Poki lists no undo for Rotate, so a turn into spikes costs the attempt.
Measure the hold in Blumgi Slime
The longer you hold the mouse button or Space, the further the slime jumps. Change the hold by a fraction each try instead of picking a new length at random. The restart button in the top corner starts the stage again.
Click inside the game frame first
All three games sit in a frame on the CrazyGames or Poki page. Until you click inside that frame, the arrow keys and Space scroll the page. Click the game once, then use the keys.
Puzzles without jump timing
Apple Worm, Lava and Aqua and Nonogram Square wait for your next move and run no clock. The comparison page lists their undo and restart controls.