Basically what the title says, itch.io are completely ignoring me and my game isn't getting indexed, as an up and coming developer this was my first test for itch.io can't say I'll be uploading any future titles here
You are a first time seller and indexing takes longer for such projects. Indexing for a project can take a month and longer, if it is on the waiting queue. Your other project got indexed.
Indexing is a bonus feature on Itch. Itch will not promote the game for you. And Itch typically does not answer indexing related questions.
Having no demo version for a paid game is very unwise. This is not Steam.
You did not link to your Steam. There are places for such social links for a reason. You can even give buyers a Steam key.
Having an installer is not done on Itch. Games that have these are either very old or very suspicious. The common method of "installation" is unzip and run. For a simple arcade type game like yours, which could have been a web game, it is even more strange.
Also, read this /t/4120453/unofficial-search-and-indexing-faq and read the rules of the message board category.