My custom HstoreQuery, this is a hacking solution with typecast on hStore value for comparison. My model already infers the data type.

hstore_query.rb

class HstoreQuery

  attr_accessor :klass, :hstore_field, :parent

  # parent = Game.first.players
  # a = HstoreQuery.new Player, 'game_values', parent
  # a.search 'float_money', '>', 9
  def initialize(klass, field, parent = nil)
    self.klass = klass
    self.hstore_field = field
    self.parent = parent
  end

  def search(field, operator, value)
    get_actor
    query = "(#{self.hstore_field} -> '#{field}')#{get_type(field)} #{operator} '#{value}'"
    @actor.where(query)
  end

  # [{field: '...', operator: '..', value: '...', connector: 'OR'}, ....]
  # arr = [{field: 'float_money', operator: '>', value: '0', connector: 'OR'}, {field: 'boolean_funny', operator: '=', value: 'false', connector: ''}]
  def array_search(conditions = [])
    get_actor
    query = ""
    conditions.each do |c|
      query += "(#{self.hstore_field} -> '#{c[:field]}')#{get_type(c[:field])} #{c[:operator]} '#{c[:value]}' "
      query += "#{get_condition_predicate(c[:connector])} " if c[:connector]
    end
    @actor.where(query)
  end

  def keys(limit = 6)
    query = ActiveRecord::Base.connection.execute("SELECT key, count(*) FROM (SELECT (each(#{self.hstore_field})).key FROM #{self.klass.table_name}) AS stat GROUP BY key ORDER BY count DESC, key LIMIT #{limit}")
    query.map { |x| x }
  end

  private
  def get_actor
    @actor = parent.nil? ? klass : parent
  end

  def get_type(field)
    temp_field = field.split('_')
    if ['int', 'decimal', 'float', 'boolean'].include? temp_field[0]
      "::#{temp_field[0]}"
    else
      ''
    end
  end

  # Just in case to use Squeel or Arel.
  def get_condition_predicate(connector)
    if connector == 'OR'
      "OR"
    elsif connector == 'AND'
      "AND"
    else
      ""
    end
  end
end