Ok I really enjoyed this game. Great sounds/music/graphics and wonderful gameboy feel! Thank you.
Also the mechanic of tether was well implemented. Unless this is built into the engine that was likely a hard mechanic to get right and it was well done and an interesting mechanic that I haven't seen in any games I've played. Kudos.
Feedback on issues/suggestions. The reminders of needing to pull back the tether aren't really needed later in the game. If I've gotten to those levels I already know to use this as you can't get through without knowing this and having it down well.
The dialog when you got the last battery was a bit frustrating. It took up time to dismiss it so I usually got punished by the dialog. I'd either remove it or make the creatures pause during the dialog. And maybe only do it for the first level.
I think that the rotation of the creatures shouldn't cause the player to get hit, though I can see this as part of the challenge. It felt like the hitbox expanded so made it difficult in some sections.
Also part of the challenge was with how the character walked, I can see this as adding challenge to the game so maybe leave it but it was a bit frustrating at some of the more narrow sections to get right.
Would be cool to support gamepad if possible with the engine. Might have helped me with my limited keyboard/mouse game playing skills. LOL