Hello and welcome to Feedback Quest 9! My name is Hythrain, and I'm one of the hosts for this lovely event! I'm also one of the streamers, so both the game and this feedback are being done live! If you want to see the see the VOD, let me know and I'll link you to it when it's uploaded to YouTube!
I'm always down for a good vampire survivor game, and this one was surprisingly well done. What I really liked was how it has a built-in autoaim for the player, meaning all the player has to focus on is moving around (and building defences, but we'll get to that). I would've loved to see more animation from the zombos and the player, but for what it is now it's pretty good. Of course, there's room to make it better and I hope to cover the major areas of improvement right now.
First, I found it generally annoying that there wasn't the ability to visit shops between levels. I particularly felt this during the second level, when enemies were coming in so fast that I just didn't have time to do anything but fight. Part of this is due to the level structure, where the spawns are very close to home, and part of it is just how fast they appear compared to the levels before and after. I almost felt like it should've been the setting of the last level rather than the second.
I also felt like it should possible for the player to set up their defences before zombies start coming at them. I like the idea of some zombies roaming around that the player can kill to earn some starting cash, but I feel like the round shouldn't stop properly until they hit some sort of confirmation. That way, the player can take their time to learn the map and plan their defences. As a fun trade-off, this then makes it easier for you to give larger waves because now the player should feel more prepared for them.
Speaking of defences, it should be possible to pick up any placed defence item and to move them around. That way the player isn't screwed by a misclick.
I liked the randomly spawning chests that give the player more money. However, the player shouldn't have to wait for the money to spread out on the ground before it can be picked up. Instead, money from chests should just go straight to the player. I also don't think that money should despawn.
When it comes to shops, in particular the store that lets you get more defences, I'd say that instead of making it that what the player can get is completely random every time they buy something, make it that everything is accessible but the costs for each specific type of upgrade rises as you buy more of it. When I was playing, I just put my focus into grabbing any upgrade that affected my nail gun or my barricades, and typically I was always getting at least one of these. I had something like 8 nailguns that had huge range and did tons of damage, trivializing the third stage. Making it that you can buy everything but each time you buy that upgrade ups the cost of the next one means focusing on specific upgrades will eventually become too costly to be worth it, which in turn will encourage them to grab other upgrades.
Lastly... I'd say drop the voiceovers of "Begin!" When you hear it once, it's not a big deal. When you hear it several times in a single level, it can get really annoying.
Overall, fun experience! Hope you do more with it!