What was this?
The weapons were a ninja stars, a believable projectile, and a sword, which is also a projectile somehow. Ignoring that, the upgrade system is just too similar to a very famous shooter game with upgrades that have similar effects. Small World, ey? The animation was very good.
To sum up the problem I think we can all agree on is that the sword is a projectile weapon that your using to kill people who stand still.
I don't think more explanation then that is needed, the reason being similar to how you can work out what a seed hole is for by it's name.