Yeah, the idea was that later in the game you could also increase area of damage (there's an upgrade for that) which would promote hitting multiple enemies at the same time and there could be upgrades that gave additional damage for each attacked square, for example +5% or so.
I'm glad you liked it and again thanks for playing. It was intended as a small project but hopefully next time I'll make something bigger and better and I'll take your feedback into consideration. :) thanks!