I really liked the meteorites in the boss battles. They add a feeling of epicness, although they're quite inconsequential most of the time.
I had an interesting run with the spark wizard. I managed to max out the sparks and that was a sight to behold. Here's a video (I'm not sure if you have time to look at these videos, I just try to record them in case something interesting happens): https://is.muni.cz/de/darek/horde-v17-sparkwizard.mp4. I think that at least the last 6-7 minutes are quite awesome, in spite of the fact that I was defeated at the end.
By the way, there is a weird bug that can be seen at ~23:25 in the video. I got healed for 1 HP for some unknown reason. (There's another instance of this at ~26:05.) That was very unfortunate for me, because I had previously used the supercharged potion and so I had a lot more HP than my maximum allowed. However, there's another bug that will discard any HP over the maximum when you're healed (I suggest first checking whether the player has more than maximum, and if so, the healing should be skipped altogether). So due to this weird 1 HP heal, in fact 50 HP have been lost. Maybe that has something to do with my premature death 😃.
Another by the way: there seems to be a big need for AoE now. The start has always been rough for the archer, but now, when the rats are smaller than before, I'd say it's a bit too much. It looks like in order to be viable, the archer needs to obtain the fireball as soon as possible; otherwise he will be destroyed simply because there will be more monsters coming than he will be killing. When I tried a run without fireballs, I had a huge tide of monsters tailing me, and by the time the grey orcs started coming, the horde still contained rats! Starting the bow at 3 arrows seems to be even more needed now.