Its ok but needs work
You have the beginnings of a good game here its a little flat though. Let me list the short comings.
1 No upgrades for you defender.
Your going to need more then just buy more fire stone of ice magic attack spells. Better armor better weapons improved defenses for the coffin.
2 Too easy to lose a weapon when killing attackers.
When playing a game like this you dont want to lose an advantage by accidentally walking over something less powerful.I walked over that stupid broom more then once and never even saw it because of corpses stacked over it. If you wanna have dropped weapons that's fine but give us a choice to pick em up rather then just pick them up automatically.
3 Enemies can hit you while you hit them.
Most gamers really hate this not much else to say about fixing it then just how annoying it is. Please fix it.
That's about it I only played through a few levels before I saw how repetitive it was gonna be. On the plus side your game has good graphics not really over demanding on a computer the combat isn't to bad apart from the one thing I mentioned earlier. I like the whole concept of your game as well. Fix this game up and itlls be a great defense game.