Really solid entry!
First of all, I really like the concept of having two weapons you switch between as you fight. The charging mechanic really encourages you to switch back and forth to take full advantage of your energy recharging as well as take advantage of elemental advantages/disadvantages. There was an impressive number of weapon types and all of them felt different to play, even within the same class but with different stats.
This is a game where the "monster house" style of enemy spawning worked really well. I especially liked how the music instrumentation changed during combat.
Biggest areas for improvement are probably just an extra level of polish (like movement animations for the player). I do think the super effective/not very effective hints could have been clearer (I noticed part-way through the numbers had a color tint when dealing damage). Different sound effects would have been a great indicator here --- then again, the game was made in a week, we didn't even have time to put sound effects in ours at all.