Nice, looking good! They really fit with the style of your game. I'm glad you like them!
The explosions in this pack were made with a custom particle system tool, which is quite out of date now but maybe in the future could see a revival.
However, I hand-draw a lot of pixel art effects lately if you're interested in something with less FPS but a lot more style and polish:
- Super Pixel Effects 1
- Super Pixel Effects 2
- Super Pixel Effects 3
- Super Pixel Impact FX 1 (Might fit well with your game)
- Super Pixel Sci-fi FX 1
- Super Pixel Fantasy FX 1
- Super Pixel Blood FX 1
I'll definitely do some packs of hand-drawn explosions this year!