This was a very technically impressive game, featuring many complex systems and game mechanics. And while it’s very clear where the game pulls its ideas from, it certainly has a “Creative Direction” that helps it stand out as something unique.
First I want to talk about the art. The backdrop that the game is built on top of has a really well done painted look to it (Maybe even hand painted and scanned in?). However, I think the game could have done a better job of presenting it. When the player first launches the game, the backdrop is already covered by fairly boring UI fonts and boxes. I’d suggest something like fading the game in from black to the full shot of the city, giving the art a moment to “Show Off” before fading the UI elements in.
Speaking of the game's UI, I think the font and general style is quite basic. And while keeping things easy to read and understand should always be the top priority, the visuals here tend to clash with the detailed backdrop and “Creative” character. With more time, I imagine you could have looked for a way to blend these elements together a bit more seamlessly, without impacting the readability.
As for the characters, they are certainly a unique style. But since most of them follow a similar meme look, which ties them all together well enough. And there's a lot of variety, which helps keep things from getting boring.
Unfortunately, the combat visuals do leave a lot to be desired. Most autobattlers thrive off the idea that by late into the game the fights become large scale spectacles. However in your game, it's difficult to read what each character is doing, and the attacks themselves have no weight. Leading to the fights feeling like a number simulator rather than a real battle.
To make the fights more interesting without blowing up the art budget, I would suggest a few ideas. Characters could have a small animation where they briefly move/nudge in the direction they are attacking, projectiles could be larger and include some kind of particle, enemies could flash red when they are hit and have some squash/stretch, and when enemies die they could spawn some smoke or other death particle in their place.
As for the audio, I think the sound track works well with the pacing of the game. The tempo makes sense for a strategy game, and its loop is long enough to not get annoying. There is a slight pause in between loops, which is a bit distracting, but overall not a big deal.
The sound effects you have in game work well enough to give player feedback for when they buy, sell, or reroll. And the level up sounds are a good indicator since there's not always clear visuals for what tier a unit became.
However I would suggest adding many more sound effects to the game. Adding sounds could give the player more feedback, as well as make your fights a lot more interesting and clear. Things like a sound to notify me when I’m about to run out of time, as well as effects for when my units attack, get hurt, or die. Even little things like clicking buttons or moving units having a sound would make the whole game feel more complete and satisfying to play.
Next I want to talk about the gameplay. I think you did a great job of recreating the traditional auto battling formula, having a large variety of unique units and groups that all seem reasonably balanced. The buffs from synergies are reasonable and seem worth it in most scenarios, leading to some thought when team building.
The overall difficulty of the game isn’t very high if the player already knows about auto battlers, but it's better to have your game be too easy than too hard (A mistake I often make when designing games). Although, I would have preferred a proper “Ending” over the endless survival approach (Even if you still wanted to give the player the option to continue forever after winning). As having a defined ending to balance the game around gives the player much clearer feedback on if they are doing good or not. As it stands, I made it to round 100+ multiple times, but I have no frame of reference for if that means I’m having a good run or not. In “TFT” the defined ending is when all other players die (Which is usually around the same number of rounds). This leads to dynamic early vs late game builds, where maximizing your efficiency in the timeframe is preferred over always going for super good scaling builds.
Additionally, it's important to remember the context that your game will be played in. Since you are not a multi-million dollar studio with a huge following and competitive scene, but rather an indie developer making a single player endless survivor, your players will only continue to play if they can easily understand the game. Because of this it is very important to include some kind of tutorial, or introduce the player to mechanics slowly.
As it is now, the player is hit with a huge overload of information without any warning from the moment they hit play, all of which needs to be digested on a timer that the player may not even realize is running. And while you may feel that any player that already knows “TFT” or similar games would pick up on how to play, since your game has many subtle differences it's easy to get lost trying to decipher which elements are the same or different. If you don’t have time to make a proper tutorial, even a button on the title screen to display a simple screenshot of your game with text describing each feature is better than nothing. Even after playing the game many times past round 100, I still don’t know how many of the little interactions in your game work, which makes it hard for me as a player to improve at the game.
But after playing the game enough to understand all the mechanics, I did find the general loop fairly fun. I think all the unique synergies having multiple tiers of unique buffs made trying each one out a good time. And the units had a good balance of tanks, melee, and ranged units (Even if it was hard to tell who did what with just the visuals). After a while the units did all feel very similar, since I don’t think any of them had unique effects (Or if they did it wasn’t clear). But with the game being rather simple, I think the synergies and stats give enough reason to pick different units.
Overall, I’m pretty blown away at how you were able to build so many complex systems in such a short time frame. And I think with a bit of polish and clarity, this game could be a very addictive “pick up and play” version of a traditional multiplayer genre. I apologize if this review was a bit much, but I'm doing this to all the games from this jam as I think critiques help us grow.