Wow, quite surprised with this one!
I have to admit that my first impression of the game wasn't great. While the game had a rather professional feel for its presentation in terms of graphics and sound, the game seemed to be a rather unchallenging and standard platformer that felt rather directionless and confusing from the way it just plops you into the world. Even accepting it for what it is, I found myself constantly having my jump inputs ignored when I tried to jump from the edge of platforms, frustrating me to no end since falling is instant death, not just damage, and lots of progress was lost. The graphics, as nice as they were, could also be a bit overly busy to the point of confusion: there was a pitfall that was practically invisible between seats on the train in the section with the first heart upgrade you can get after the forest world, for example. The only thing keeping me going was the rather mysterious and intriguing feel the game had to it with its story (or lack thereof), but as I made my way through the forest picking through all these text logs and letters for unrelated stuff, I was worried it was just gonna be some sad artsy-fartsy crap, haha.
However, as I made it through the forest which slowly got more challenging and puzzle-like, had a rather impressive boss fight against a bear, marveled at how much the world was recontextualized with the pogo stick upgrade, and made my way through the bonus zone for a collectible, I was hooked and wanted to play more and more! It was a slow, rough start but I could finally see a glimpse of the gameplay loop and wanted to see what new worlds the train would take me too!
That said, the issue with not being able to leave the game and come back to a checkpoint, only the start of the level from a train, was incredibly annoying when it first happened to me as I Iost a lot of progress to the point of considering quitting the game altogether since it seemed incredibly illogical and annoying, no matter the excuse.
I haven't beaten it yet, but I'm looking forward to coming back and seeing what else the game as to offer: I just need to find a good amount of time to set aside for this due to the whole save point issue!
EDIT: I've now made it through the temple level and got the shooty and all that. It was definitely another grand adventure, but I will admit it was quite exhausting and stressful and not in the best way. Through a combination of cramped corridors, limited space, spongy enemies, and so on, the game just seemed to be overly forcing you to deal with these encounters and traps with no wiggle room, and it made it very tedious. Many times a pack of slimes would be in my way and the only safe way to engage would be to tediously lead them back several paces until you could kill them: this tedium led to me just wanting to push back them and take the damage just so I could keep the pace up, for example. Not only that, there were a lot of traps like with the rotating turrets that didn't even seem possible to get through without taking damage, and it almost seemed like the game just gives you health items around the trap as an inelegant apology for recognizing that it just couldn't be designed well enough to let you not take damage at all. I'll still try and continue, but like I said, these design choices are really weighing me down and making me lose the will to go on.