Very enjoyable.
I remember when games used to be like this. I think I still have a few of them around somewhere and this definitely took me back to my youth.
I thought that it was too easy at first, but the difficulty soon picked up. I don't remember the games from my childhood starting out quite as simple as this one started, so perhaps you could make the minotaurs move a little faster at the beginning.
The first time I played this, due to the way the flash was presented with the game and watch on-screen, I thought the only way to move Kratos was to click the buttons with your cursor. It wasn't until I re-read your authors comments (this time paying more attention) that I realised you could use the left and right keys on your keyboard, so perhaps you could include some in-game instructions for those that jump straight in. I'm sure this game would be absolutely amazing for those that have a touch-screen monitor.
In both modes the game seemed to get a lot easier around the 40 kills mark. At this point instead of there being more than one minotaur on-screen at a time, there was only the one (this lasted until the high 40s). I'm not sure if this was intentional for whatever reason or if I've encountered a minor glitch.
It was definitely great to see these kind of games recreated in flash and I'm pleased that you decided to come up with your own game instead of simply re-making an already existing one.