I really like the graphics in this game, everything is pleasantly shiny. Most especially the environment and the health items.
I can tell there were more mechanics on the way in, defending a castle from these guys would be fun, or harvesting the axes they drop and building something out of it.
On your Sound Queues, check out the concurrency setting. Sound got a little harsh when I killed a bunch of clumped up robots at once.
Once you figure it out, it's not too hard. Honestly the low difficulty made it easy to keep playing for longer than I probably should have, I made it to wave 23.
Very well-polished (no pun intended) for a game jam, great job