Okay this is a bit tricky to review short so bear with me.
The start is quite confusing and need quite a bit more polishing, it took me about 20 min to even realise how fun it is and how much potential there really is!
I think this game is about a third ready to be released on steam for 10$ which is unbelievable good for a jam game! I see that the html build was broken initially, but if this game doesn't get 5/5 it's only because people didn't stay long enough! I might sound hyperbole, but this is by far the closest to a be a "real" game I've played this jam, and I've played some games I thought were great entries. It really scratches the same itch as "Gnorp Apologue" or "Rouge Tower".
The simple graphics are great! The particle effect when enemies dies feel solid and the tower shooting feels really satisfying. Levelling up attack speed felt super nice. I like the concept of the summoning, it feels just enough to make it to sort of a "rouge idle game" rather than a pure idle game.
I think it would have been a good idea to let the player start with one card in the deck so you have something to interact with from the start - so far after playing it about an hour I think its more of a idle game, and a great one at that, with some interactions once in a while. But when starting it just felt a bit slow, and I was wondering when I get to play my cards.
It also took me a couple of rounds to realise that the money you spend during the game isn't spend when going out to the shop. I think that could be a lot clearer. I think the most simple way would be to split it up into two currencies, so for example "mana" to play cards and $ for the shop. Then you could also have a passive mana reg stat.
The wave meter is a bit confusing that it takes two laps, one red and one green. I haven't figured out if that means something, but if it doesn't, it probably should just be one slower lap. I still haven't been able to click to the next tier, and I've survived around maybe 30 waves. Don't know what's up with that, but if it is just because I havn't reached it yet, it would be nice to have some indicator for how many waves I need to survive. Or if it just that I cannot figure out how to change tier I guess I find it confusing how to do that :P
I've upgraded my base tower quite a lot, but since I still need to start from the beginning it feels a bit slow in the beginning of each round. It would be nice to pick what wave to start or that higher tiers were reached quicker (maybe they could be bought with upgrade money). Also I would like to be able to abandon current round. I accidentally started a game without upgrading the "tower" which is what sent me out here to write this review instead of continue playing.
One thing I could be iterated upon is how you get money, since the enemies are scaled but not the money you get it feels a bit pointless to play card if you see your gonna die soon and you will get the same money after restarting against easier enemies. So maybe you could be 23 * X $ for clearing wave 23, or more money per enemy the longer the game goes.
I still haven't dwelled into the deck building component of the game (I have only bought two poison clouds), so I can't really give much feedback on that yet. But the visual is nice, but since the game is so minimalistic in general I think it could be nice with a circle outline of the exact area it hits. Also some indicator of how long it lasts, maybe on the card itself to not clutter the game screen. I don't know if it's random what card you get, so maybe I was unlucky, but I got two poison cards and that doesn't seem to give me anything since there is no cooldown. I think maybe it got upgraded(?) but if so I feel the second card is still unnecessary.
Sorry for the wall of text, I just really like the game and think it has great potential! I'm gonna get back playing now. Well done!