Any Game Ideas that I can develop as a solo developer

Hello everyone, I am really sorry because this question isn't really developer-related but I do have a little problem. My main goal is to make a game, I was thinking about making a chaotic / funny games that you can play with up to 8 players/ friends. I already established a group and a icon for that group, but I'm stuck on a game concept and what type of game to make. If anyone wants, can you suggest me some fo your top ideas that I can develop (Primarily co-op game, which I can release as a beta by April). If I like that game idea and it gets pretty popular I'll award that person with Robux! Thank you in advance.