Would be a lot easier to say something about the SFX from a video. Now it's mostly random stuff happening here and there and as a listener I don't know what to expect. But nevertheless they sound quite good and appropriate for their genre.

Your 8-bit stuff is good. Sci-fi is also OK but every sound is somewhat similar to each other as if they're filtered with the same preset.

Piano/drum theme depends on how long the player would stay on the menu screen. It gets repetitive at some point so you could try to grow it up a little bit later on.

Zombie stuff sounds quite weird, like cows or moose. I think you've just slowed and pitched down your sounds and therefore they lack the high end and anything that gives them interest. You can try to maintain (mix in) some of the original sound to give it a little crisper feel and add some gargles/breath/etc. at normal speed/pitch. Use layers and saturate to glue together.

In most cases any sound effect needs its highs, mids and lows to sound realistic. They can be different layers to be more easily controlled. So if you lose your highs or lows when altering speed/pitch be sure to bring it back somehow. Of course there are exceptions like really small creatures that don't have any low end in their sounds.

I'm happy to re-evaluate your sounds if you decide to redo some of them at some point :)

Would be a lot easier to say something about the SFX from a video.

Your 8-bit stuff is good. Sci-fi is also OK but every sound is somewhat similar to each other as if they're filtered with the same preset.

Piano/drum theme depends on how long the player would stay on the menu screen.

I'm happy to re-evaluate your sounds if you decide to redo some of them at some point :)

Thank you very much for you feeback, I found it really helpful! I will rework them for sure ;)

So about SFX it would be better making a video reel to use as demo?

About zombies, you got me. I pitched down some animal sounds, a crying babie and cats..and I agree they lack high content and other sounds to be more credible.

Sci-fi stuff sound similar cause I used a VST granular synthesizer manipulating a single sound in different ways. Should I add other high freq sounds to improve the result? or should I use a different approach?

Finally, about piano for menu screen I completely agree to add some instruments to give more enegy at some point.

Thanks :)

Video reel would be great for SFX. It's easier to connect the sounds to their source when watching a video. Also working with a video gives you borders to work with and it's closer to real sound designer work. Just find some inspirational gameplay videos or movie clips and start with documenting what kind of different sounds you need for it.

Sci-fi: Your approach is good with granular synthesis but again the problem is that without a video it's hard to tell what is the origin of the sound. Is it a space ship or some kind of a machine or many ships flying by. For many different ships the sounds are pretty similar. Maybe some could sound different than the other. Video would be great for this also. Then you can pan & doppler the sounds with the video and it shows more of your talent.

One of the most important tips for creating SFX is layering. Very rarely you happen to find/create a sound that is usable by itself. Most likely you have at least 3-4 layers glued together. Start with some good sound and think or try out what would make it even better. Add some high freq sparkling or a sub kick and think how the sound should start and end and how the layers are timed. For example some kind of a magic missile: Start with a bang/explosion with a sub kick, add some fire whooshes and end up with sparkling top layer. Just some tips :)

Keep up the good work :)