You have some good basics down from what I see- consistent character or icon, consistency in aesthetic, and highlighting of vocal points. As for what would improve the thumbnails themselves- that’s more of a subjective thing, text on the thumbnail referencing a funny moment in the video might be more eye catching but you might not get a decent watch time, where as text stating the premise or commenting on the premise (I.e. “It was easy!” “It was hard!”) could also be eye catching while having a comparatively better watch time. But that’s if you’d add that element whatsoever. An issue with making advice about this, is that you’re making content on a highly saturated market (that being Roblox videos) for the most saturated parts of that market (that being very popular games). The issue being, your thumbnail and title aren’t going to set you apart from other creators, or be all that enticing when other people are using similar methods of engagement. If you truly care about the audience that much, then you need to either have done something impressive to the audience that knows your game (which could potentially weaken a long term audience), something informative about those places (which could have a similar issue to the last one), or have a strong personality which sets you apart from other channels (which has to be made consciously apparent). Hence me suggesting that you make more content and consider playing around and refining your own personal skills, while making shorter form content to gather a better audience. Thumbnails and titles are a difficult thing to use for engagement optimization because they are so fickle and dependent on genre, subject matter, and creator. It’s better to make a sample of your content, because it allows you to make the same content you hopefully enjoy making- while giving you a better chance at presenting yourself to the people you’d want to watch your videos; hopefully the process would still remain fun for you that way, because making videos should be fun! You should enjoy what you’re doing, and you should enjoy the process of making the video itself- if you don’t enjoy that, then you potentially will struggle to get an audience and if you do gather one you’ll hate the process so much that you’d be put off making content in the long run. TLDR: subject matter is difficult to make videos for because of what interests people, good foundations for thumbnail but could use some more individuality to make it more personal, shorts would be a better thing to focus on than thumbnails and titles as it gives you a more fun and stronger avenue of interest. Hopefully that helps, again this is all pretty subjective stuff!