First, excellent art, lots of great small details and animations, plus the protagonist robot has this cute charming design, playing around with light/shadows, top notch for a pixel game. The music is also pretty good adding to the horror ambience and there's even nice voice acting!
Now as for the gameplay itself, it felt solid but nothing particularly revolutionary. Gather items, craft upgrades, some memorization/switch puzzles. They felt a bit too basic personally, usually other pixel horror games have more complex puzzles to advance I feel. Although that may be this game's design choice to keep the puzzles more basic than your usual pixel horror game, nice and simple, in which case that's a perfectly valid decision. Speaking of which many horror games have "sudden death" moments when you pick a wrong option or screw up a puzzle, that seemed missing here too for the most part except for the bits where you're trying to escape the Lurker and you'll lose if you run directly into them. But then when there's a puzzle on the escape route, the Lurker will seemingly wait if you screw up said puzzle's resolution, which diminished the horror effect personally. It seemed to be the perfect moment for the Lurker to edge closer and closer every time you fail a puzzle (maybe even slowly approach continuously so the player is on a "timer".
Then as Atas Fun pointed out, there's a significant shift in gameplay when you unlock combat. Suddenly the cute unarmed protagonist robot gets a sword and a gun and a bunch of special abilities along two special resources to manage and can take on the monsters. I think that could've been handled a bit more gradually. First sword, then gun, then special abilities for example. Also the smaller monsters could start showing up earlier, before you get any combat upgrade you need to evade/avoid them. Maybe they're used as roadblocks earlier on, then as you get combat upgrades you can now start exploring those areas.
Related, the protagonist gets triple digit HP right away, when the enemies deal single-digit HP. That leads to the protagonist being slowly but surely worn down over multiple battles. I don't think that's the ideal way of doing things, what many games nowadays do is making characters more frail but giving easy access to some sort of limited replenishable healing item, like Dark Souls flasks (can be used a limited number of times, but refreshes automatically when you respawn/rest). If there's an HP mechanic, it's usually more enjoyable to have an easy way to replenish it a few times rather than seeing a large HP bar slowly withered down.
Also enemies felt a bit too tough for the damage they dealt. It somewhat diminishes the horror aspect if battles becoming slogging matches.
My nitpicks aside, great work overall, this game had clearly a lot of effort and planning put in it, excellent ambience and general presentation, lots of small cute details like the collecting cards, just the combat could feel less grindy and better integrated with the main horror aspect.