The balloon in Balloon Guard has no health bar and no recovery state. checkBalloonCollisions tests one circle of radius 28 against every obstacle, and the first overlap calls popBalloon and ends the run. Durability in this game is a property of your shield work, so treat any advice about balloon HP as fiction.
The one hit rule
The pop test is exact. Blocks and bars use a circle to rectangle overlap. Circles and spinners use circle to circle. Spikes test against radius times 0.9, so a spike kills from a slightly smaller distance than its drawing suggests.
The balloon drifts on a fixed path. Its center stays within 3 pixels of the screen center line horizontally and bobs 6 pixels vertically, and it rises at a constant 40 pixels per second. You cannot steer it. You defend one column.
Shield physics you can plan around
The shield is a circle of radius 36 that follows your drag. On release it drifts back to a resting position 120 pixels above the balloon, which is your default guard spot.
A shield contact does three things. It separates the obstacle by 0.8 of the overlap depth, reflects part of its velocity, and adds a push of 400 times (1 plus 0.2 times difficulty) scaled by 1 over the obstacle mass, with that ratio floored at 0.5. Mass values come from spawnObstacle.
1. Blocks have mass between 1.0 and 6.5.
2. Horizontal bars have mass between 3.0 and 9.75.
3. Circles have mass between 0.98 and 5.12.
4. Spinners have mass 2, spikes 1.5, and wave rain circles 0.5.
The push ratio inverts that table. A rain circle at mass 0.5 takes the maximum ratio of 2.0. A full length bar at 9.75 takes about 0.10, ten times less. Deflect circles early and treat long bars as weather to route around, because blocks and circles bounce off the side walls and a deflected obstacle can come back.
The unlock schedule
Difficulty equals 1 plus elapsed time over 30. Obstacle fall speed equals 40 plus 25 times difficulty, so 65 pixels per second at the start and 140 after half a minute. The spawn interval is 2 divided by difficulty, floored at 0.6 seconds.
The engine gates obstacle types behind difficulty thresholds, which map to clock times.
1. Blocks and circles spawn from the start.
2. Horizontal bars unlock above 1.3, which is 9 seconds in.
3. Spinners unlock above 1.8, which is 24 seconds in.
4. Spikes unlock above 2.5, which is 45 seconds in.
Plan your first minute knowing the hazard list only grows.
Survival routine
1. Leave the shield parked above the balloon when idle. The engine returns it there on release.
2. Hit circles and spikes off center, on the side away from the center column. The push follows the contact normal, so your approach angle chooses the exit direction.
3. For horizontal bars, position early and shove the near edge to steer the gap over the balloon column instead of trying to stop the bar.
4. Collect power-ups with the shield. Freeze stops every obstacle for 3 seconds and restores the exact saved velocities after. Double shield widens you to radius 72 for 5 seconds. Slow halves obstacle speed for 4 seconds. A new power-up floats down every 15 to 20 seconds.
5. Count waves. Every 30 seconds a warning shows for 2 seconds, then a wave pattern runs 5 seconds and pays 100 score on completion. Rain drops 15 circles across the width, walls close two bars with a 100 unit gap, spiral sends 8 circles inward.
6. Score is height divided by 10, plus 50 for each 500 height milestone. The balloon covers 500 height units every 12.5 seconds, so each milestone adds 100 total score on a fixed clock.
Where this implementation hurts you
The shield never destroys anything. Every obstacle you deflect stays in play, and wall bounces send blocks back across your column.
Heavy bars barely respond to pushes as difficulty climbs, because the push force grows with the same difficulty that speeds the obstacles up.
The idle return drift is slow. If you drop the shield during a spike phase, it crawls back at a 0.3 lerp factor and leaves the balloon exposed for a moment. The physics update also clamps its time step at 0.05 seconds, so on devices below 20 frames per second the whole game slows rather than skips, and your timing memory goes stale.
Balloon Guard survival checklist
- [ ] Shield parked above the balloon between threats.
- [ ] Circles and spikes deflected off center, away from the column.
- [ ] Bar edges steered instead of blocked head on.
- [ ] Power-ups taken with the shield, freeze saved for converging waves.
- [ ] Clock watched for the spike unlock at 45 seconds and waves every 30 seconds.
Play the [Balloon Guard game](/en/rise-up) and test the deflection angles against the mass table above. If a specific obstacle type behaves differently for you, note the elapsed time and the obstacle kind and send it. Anomalies at the unlock thresholds are the most useful data you can contribute.
