(Note, I am not a linguist, expert, pro or anything) I have once asked myself, what makes a language sound beautiful? My answer now is: There is not 1 way, there are infinite. And tastes differ. Languages have a certain feel to them. When you hear more and more languages you will see just how different they are and how there are so many beauties in their own ways. Take this into account: The phonology (duh), the phonotactics, the prosody (don't under estimate this one). I see that you chose a small phonological inventory. Cool. For the consonants you chose no voicing distinction, one fricative, two stops, a nasal and an affricate. You also have a 4 vowel system. I expect some allophony since your inventory is small. For example, voicing between vowels, /ts/ may have /s/ as an allophone. /n/ maybe with /l/ or /ŋ/. /ɑ/ with /a/, /ɛ/ with /e/, /u/ with /o/. These are just examples.See what you can do. As for the phonotactis you have (C)V. If I did my math correctly, that gives you a maximum of 24 different syllables. That does leave for quite few syllables. If you don't want to risk super long words you could add pitch or tone to your language, or maybe phonemic stress or vowel length. Most natural languages do have something of a CV structure iirc. But they do have a little twist that makes them their own and distinct. Japanese allows syllables like wo-ku-shi, To-kyo, kon-ta-mi, etc (I think). So, mostly (C)V, but its distinction in the phonotactis is that it sometimes has a 'y' between the C and V. So you get To-kyo, CV-CyV. And it can have a 'n' after the V. So ran-ti-wo. CVn-CV-CV. Experiment with that. Prosody, I have less to say about that. There is actually a lot to it. It is basicly how your language is 'sung'. I don't know if this is included in prosody but, consider this too. Languages can be stress timed, syllable timed and mora timed. English is a stress timed language. In a sentence you have words that are pronounced harder and longer. "I'm watching Spongebob with my kitty."

I'm WATCHING SPONGEBOB with_my KITTY." These are I guess the more important words. The non capitalised words are pronounced shorter and less intens than the capitalised words. "I'm watching episode five of Spongebob with my furry kitty." -I'm WATCHING episode_five_of SPONGEBOB with_my_furry KITTY." The words around and between the stressed words are pronounced with rougly the same amount of time, no matter the number of these unstressed words. The stressed words are pronouned a little longer and more intense. Spanish is syllable timed. This means that every syllable in a sentence is pronounced with roughly the same amount of time. I don't speak Spanish, so this will be gibberish. "El taco estas loco." El-Ta-Co-Es-Tas-Lo-Co Let's say this sentence takes one second to say (I timed me saying it). There are 7 syllables, so each syllable should take about 1/7 of a second to say. Mora times languages: Well, I don't know the term for this, but basically you have two kinds of syllables. A normal, let's say CV (pa), syllable and I'll call the other one an Advanced syllable. The 'Advanced' syllable is one that has a vowel that is not 'plain'. So it can be a long vowel (pā) or maybe a diphthong (pau). These syllables takes up timing units. Let's say a normal syllable takes 1 second to say, then an Advanced syllable will take twice as long to say. So a Normal syllable takes 1 timing unit and an Advanced syllable takes 2. When we have a sentence: "Ka sote pā ni mau." Ka1 So1 Te1 Pā2 Ni1 Mau2 The syllables with a 1 are the normal ones and the syllables with a 2 are the advanced ones. Would it take a full second to say all the normal ones, then it would take two full seconds to say the advanced ones.

So basically, there are many ways to make a language that you think is beautiful. Experiment with different elements and give your conlang a distinct feel to give it its own unique beauty.

Wow, this comment turned out way longer than I thought it would. But, I hope this helps!