Nice little game you made there.
I really liked the simple art style of the character and room layouts and objects. Your game thumbnail is nice and punchy design as well with the Cockroach and poops lol! Almost looks like a Bug spray design on the side of the can.
Some things i would look at would be...
1. Maybe instead of left mouse button make the stomp button spacebar instead as game would be more fluid experience if on keys entirely. Also, maybe instead of a key at all you could maybe have the stomp animation trigger when you walk on them instead and just make the game arrow keys only. Then no cursor on the screen would be necessary.
2. The Roaches would look better if they were the same resolution as your character, backgrounds etc. as this would create a much more cohesive/polished look.
3. Then thirdly something that i think would have added massively to the game would be to have had Roach blood splats as you squish each bug. Random black blood splatter programmed to stay in the room until the end of the level would add a nice element to the game as you can literally paint the rooms with their blood. Also, the commenter below burning the house would be a nice element to add also lol!
Nice little game anyway was quick and fun :)