Glad my comment is useful, especially for the bugs! :) You are welcome.
I have no idea what can cause some one of them such as the boss not spawning at the 5 minute mark and why the FPS drops when shooting. The shooting might be a problem with the browser version, but the timer for the boss makes no sense.
- For the time, I guess the lag can cause some decoherence between game time and real time, depending on how the game/engine deals with game time; I know through MonoGame that weird things can happen, but I am not entirely sure this is related.
- The FPS problem seems more straightforward to me: there is so much stuff on screen (especially particle/visual effects, these are greedy!) that the processor has a hard time. X)
I will go over all your points in detail after the game jam and try to make this in to my first "real" game.
Great, good luck! :D (I also have many game jam games to take care of now, but I am caught in a succession of game jams out of creative frenzy. XD)
I am going to play and rate your game before the jam ends!
As you wish; be aware that mine is an extremely short last-minute entry! So, it should not take you much time — contrary to what yours did to me. XD By the way, do not hesitate to help out those entries with few votes (this link is at the top of the regular entries list). This time, I used the Karma ordering (watching out if the creators spammed or not), which is how I found your game. :)
Just one question that is in my (way too) long comment: does something specific happen when you get everything maxed out?