Hi, I just finished up playing ATS & have a lot of feedback for you. Just a disclaimer, no criticism here indicates that I disliked the game, I just took notes on everything that came to mind as I played the game so you could have as much feedback as possible.
First off, I really liked a lot of things about the game. The parallax effect in the windows is really impressive, I loved that. I also liked the intros to the bosses. Panning toward to mini boss at the start of the fight is always good, it lets you know that you're in a fight now, but also gives you a look around the room so you can figure out what to do right away. The beginning of the final boss fight was even better, I thought it was really cool when everything zipped off to the side like that. The final boss fight had a lot of cool visual stuff going on, but was a totally fair fight, so that was really nice.
In general, the combat and platforming were really good. It's unusal to have so many extra jumps right from the start, but easy to get used to. The controls were intuitive and the written instructions at the beginning made everything even more clear.
I like a lot of the little things, like being able to shoot the missles that the boss fires. When you go up into a room, you are put onto a safe platform instead of immediately falling back down. It seems obvious but it's something I've seen a few games forget to have, & shows you were thinking about the player experience.
I was really glad to see working save points and a resizable window. It also nice to be able to use my controller without needing joytokey or something to get things the way I wanted. Someone else mentioned the left stick for aiming was awkward, but I didn't have a problem with the shooting. A lot of games make you stop walking to attack & I think it's a reasonable thing to do.
I have to admit, the graphics and music were not on a very high level, but I didn't have a problem with either of them. A couple of the songs were pretty catchy including the one that plays through most of the game. I also liked the tiles that lined the walls, and the effects I mentioned earlier.
Some things I would like to see changed. There were a couple blind falls, and at least one that could drop the player onto an enemy they can't see. It might be good to have long downward sections not be in a straight line so the player can move down them gradually. It also would be good to have a lower "terminal velocity" for the player to have more time to react.
There were a bunch of little things I thought could be improved. None of these are very important and I wouldn't expect them to all be implemented in a game jam release, but they would probably improve the game.
The action button probably isn't necessary. You could have the player hit the attack button in any situation when they are required to hit the action button, and I don't think it would ever cause issues as the game stands now.
The game isn't visually paused during room transitions, so you can see the player move while you can't control them, & it looks really odd. It's especially noticable when you exit a room upward, because the character falls back down as the screen fades out. It doesn't cause any issues but it looks unpolished.
The mini boss doesn't telegraph its attack before it starts moving. Since it moves so fast, it's hard to deal with unless you try to anticipate it ahead of time while it's still not moving. I had a little trouble figuring out how to beat it, but eventually did. That could be helped with some extra feedback, like an audio cue, or maybe if it had something obviously defending it from attacks that breaks when it hits a wall, as opposed to just flashing some lights. It also wasn't obvious to me that those half circle areas refreshed your jump. You could just have some text on the wall the first time you see them like at the beginning. I figured it out pretty quickly, so no big deal.
The moving platforms change direction as soon as you move above/below them on the Y axis, and that makes it so they move away from you when you try to jump on them from below. It never really mattered while I played, but it's something to think about, plus it felt a little like the platform was trolling me. Also, I thought they were enemies when I first saw one. It might have been because it was slowly moving towards me, and I had just seen enemies for the first time, which also slowly move towards you. They also have red lights which are often danger signs.
The normal enemies do a very small amount of damage. It might have been more exciting if they dealt a little more, but it's good to err on the side of less damage, so that's OK. It would be good to heal the character at save points & that would let you make the levels a little more dangerous without being cruel to the player.
The melee attack was very short range & since the walking speed is so fast, it was very hard to move towards something & attack it without bumping into it. It only really mattered to me when I was fighting the mini boss & hadn't yet figured out how to fight it, so it's not a big deal.
A few glitches: First of all, the mini boss got pushed up on to the hero's head a couple times! Since it's not ever supposed to move on the Y axis normally, you might be able to change its physics to cancel any stuff like that from happening. One time I shot a small enemy, and it got "knocked back" toward me. Something to do with shooting it at an angle, I'm sure. Also, you can get an extra high jump by pressing the attack button immediately after the jump button. It looked like it might be caused by the hovering that happens when you attack in air. Is your gravity decreased when you attack in mid air? In any case, you can jump higher than intended by doing that, so it could let players sequence-break the game if there are jumps that are supposed to be too high to reach before getting powerups.
All in all, I found the game very fun & satisfying in a metroidvania way, so nice work! I hope things go well in the future expanding on the game.