As you progress into skins 11-20, the Timeline speed will gradually increase, and you'll start to encounter skins with more distinct musical patterns. This is the ideal time to begin incorporating chain reactions into your strategy. While basic clears are still important, setting up multi-square clears will significantly boost your score and help you survive longer.

Key Strategies:
- Look for Chain Opportunities: Actively scan the field for areas where you can create multiple 2x2 squares that the Timeline can clear in a single pass. This often involves placing blocks strategically to connect existing same-colored blocks.
- Stacking for Chains: Don't be afraid to temporarily stack blocks higher if it means setting up a large chain. However, always have a plan to clear that stack quickly.
- Utilize Both Colors: Try to build up potential clears for both colors simultaneously. This gives you flexibility when a block of a specific color drops.
- Adapt to Timeline Speed: Some skins in this range will have noticeably faster Timelines. Adjust your dropping speed and decision-making accordingly.
- Power-Up Blocks (Rare): Occasionally, you might encounter special 'power-up' blocks (e.g., a 2x2 block entirely of one color). Use these strategically to clear large areas or set up massive chains.
Skins like 'Heavenly Star' or 'Misty' might appear, offering a good balance of challenge and opportunity for chain building. Practice setting up simple 2-3 square chains before attempting larger ones.