Balloon Inflate puffs each letter up from nothing until it is round and taut, then lets the whole word drift on the small buoyant float of something filled with helium.
bl-inflate scales each letter up with an overshoot so it visibly stretches past its final size before settling — the overshoot is what reads as air pressure. bl-float then runs a slow independent drift, so the word never sits perfectly still.
Elastic Pop snaps in and wobbles like rubber. Balloon Inflate grows steadily under pressure and then floats — slower, softer, and it keeps drifting afterwards.