I like the particle effects in this game XD
It's so satisfying to see XD
The goal of the game is also easy to understand.
Maybe you can use limited range for the sword / cool down for each attack. That way, the game become more challenging.

I tried to play your game but unfortunately the "START" button does not work :(. I like the spritesheet though so I think it could be lovely game. 

Also just a small advice, people prefer to play the web based games, in case you make a 'downloadable' executable, add a bit of description and what's the most important - screenshots. This will encourage people to try your game :).