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Get Hydrogen old version APK for Android
Catch that proton!
Tilt your phone, move the electron (blue) and try to catch the proton (green). But watch out! You can't touch neutrons nor positrons (gray and red)!
Major game update v 2.0:
-New engine
-IAP - buy editor and hide ads
-All levels from full Hydrogen (Classic) and several new added
-Completely redesigned UI
-Sounds
-Custom maps are now stored on SD card (or mass storage if card not present)