Plain mechanics focus on clicking colors to fill areas. i find the physics a bit wonky sometimes when filling large sections. The main action is just clicking to apply paint to selected regions.
You click a color, then click the image section to fill it, starting immediately without downloads.
Controls are just clicks and taps, nothing complex at all. There is an undo button to fix mistakes and images can reset sometimes.
Most advice is to use the zoom feature for small details and fill large sections with one click to save time. Be patient and pick the right colors for each area.
Q: What are the controls? A: Clicks and taps are the controls. Q: What is the objective? A: The objective is to fill areas with colors. Q: Is there an undo feature? A: Yes there is an undo button available. Q: What is the main mechanic? A: The main mechanic is clicking to apply paint.