Wow, this was quite the manic puzzle matching game! It's kinda crazy the way it just throws you into it with no explanation, but it's pretty intuitive and fun to just start making matches based on color, and little by little you start to notice things like how the steam tiles make stuff rise up to the top either naturally or from getting clues in the upgrade menu. Overall it's a very cute and high-energy game that I had a great time with, and I was surprised at how challenging the last level could be when you'd think the game would just let you overpower it with the upgrades!
That being said, I don't necessarily want to gloss over its faults, so here's some feedback on that:
*As said, it does kind of just throw you into the deep end with no instructions. Sure you can just match colored tiles, but I had no idea what tiles were good to match and which weren't. For example, I wasn't sure whether the green tiles were actually powering the train or if there were just clutter I needed to get rid of: the way they were called 'recycle' made me think they were just to 'recycle' the board with better power tiles.
*I think the biggest issue is that the feedback is quite lackluster. It's very difficult to pay attention to the tiny map on the bottom or the tiny stats to the left while you're playing, so you can't see how much power you're getting from matches or how much time is left when you need to be. I wish there were more satisfying effects when you make bigger combos, like some speed lines and a big gust of wind: hearing the same sound effects for all combos made it feel so pointless and ineffectual. I also wish that there were some alerts that would happen in the center of the screen, like an alert when you've got 10 seconds left, or a chime that plays for every station you pass, and so on. It felt like all I could do was try and make matches blindly since I had no way of procuring data to make optimal choices.
*The sense of progression was a bit awkward where I couldn't tell at first whether the game had an end goal we needed to reach. The lack significant punishment for lateness made me also feel like getting good at the game was pointless since perhaps it's all about being forced to grind for upgrades. Once I played long enough I realized most of these were false fears, but I had no idea it was the case initially.
*As the game went on, the controls just started to get really fiddly and annoying, with me trying to click on something but it ends up targeting something else, or trying to link everything together but it ends up doing it in the wrong order I wanted, or the nuclear upgrade that lets you chain to other different powers being an annoyance you actually might want to avoid. Quite frustrating!
It's definitely got some rough spots, but for a game jam game, it's a fantastic effort with a solid foundation. Nice work!