Update! (V1.5.0)

It's been a few months since I published this here, but I've added an update to the game that will hopefully improve the game balance and experience! Here's a list of the highlights:

• I've removed a bunch of words from the word list that were actually just abbreviations, suffixes, etc. and tended to get in the way by unexpectedly being counted as words when trying to form bigger ones - this includes ARD, EEN, ING, ISH, OINT, OOM, OON, OUS, and more.
• The frequencies of several letters have been tweaked a bit in order to improve the game balance (hopefully you'll get more S's and fewer floods of H's and V's!)
• Updated score thresholds for levelling up
• Improved the system that starts altering the letter frequencies after all special tiles are introduced to have more balanced randomization
• Slightly reorganized layout for the sidebars
• Added background music and sound effects (music is off by default; both can be toggled on/off in the settings)
• Added extra score bonuses for longer words
• Infected tiles now start with no infectivity and gradually become more infectious the longer they remain in the grid
  
• Spelling the bonus word now yields a score of either the word score plus 300 points or 2.5x the word score, whichever is greater (originally it was a flat 200-point bonus)
• Fixed a glitch where if there were two words formed in the same column at the same time, the game would only recognize one of them