For a first entry, this is pretty solid all around, good bit of things to do and items to utilize that each have their own unique use that comes in handy. It's also cool to see someone else using Gamemaker as well, I am curious on how you got the enemy pathfinding to work in this game as I've never dabbled in that myself.
And if you do want to improve upon some things, I do have the feedback that at certain times some enemies would just stop moving all together, once there was a final bug on a level that just stopped moving entirely without any items/traps around it either (though upon replaying the game it seems like this happened whenever a bug would be frozen and eventually unfroze, they would still remain frozen in place). Also if used right, the block item can just stop an enemy entirely if its spawned where the enemies' moving, but at that point it seems kinda right for that to happen at that point and likewise will also stop the player if you walk back into the area before it fully completes (once I also had a visual bug where the sprite of the block trap became a red square with an incomplete circle). And then if you kill the final bug of a level and yourself at the same time, fortunately you will move to the next level, but there is a flash of the level restarting just before you do.
But of course, this isn't criticism against your game, just some bugs I found and attempted to find as feedback, because aside from that, from the artstyle to the gameplay, it was very much a great designed game all in all, especially for a first entry. I do also wish that there was a pause for the game, but I digress, it's a solid game with a good bit of charm to it all in all, good work to everyone involved.