Hi there Itstom!
After looking over your videos, I can definitely tell you are using keywords in your title and descriptions to help boost your SEO score, especially with newer videos. For example, on your newest upload (Fortnite, Apex, Hyper Scape....) you have a fully filled out description that explains what the video is about. In this description, you even included timestamps which is something I like in videos because it helps me to navigate through the video when I'm trying to find a specific thing or when I want to go back and watch a specific part of the video. I recommend trying to make all of your videos follow this video description's format in the future.
One thing I will advise you to do is to double check to make sure that all parts of your descriptions are in complete sentences (which you have done well, I have just noticed that on the same video I mentioned above the first line of the description does not look like a complete sentence). It is also recommended that your descriptions are at least 300 characters.
For tags, I recommend making sure that you have at least 200 characters worth of tags while also making sure that they are relevant to your videos. For instance, your video "Fortnite, Apex, Hyper Scape..." video has 20 tags, which is well within the character limit, but some of your other videos such as "First 20 Minutes of Assassin's Creed..." and "Getting Extremely Annoyed..." has between 3 and 5 tags. Once again, when you add tags to the videos make sure that they are relevant to your video so that you follow YouTube's guidelines with the tags.
For thumbnails, a good tip I have seen is to stick to a color scheme so that eventually when your videos pop up in search viewers will recognize that those video thumbnails and videos belong to you. For example, your first three videos on your channel all include orange text in their thumbnails. I get that you might be changing the thumbnail colors depending on which game you are playing in each video, but I think if you were able to work in a color scheme that would work for all the games that you play in your videos, it would make them even better. Overall though, your thumbnails do seem pretty decent.
Keep up the good work with your channel, I hope at least one thing I said in this review was helpful